Asnt Rt Level 3 Qns & Ans

.ASNT

Third Edition

Rodiogrophic Testing Method =-

o

Levels l, ll ond lll Review Questions Book A

NASNT

Third Edition

Rodiogrophic Testing Method =-

o

Levels l, ll ond lll Review Questions Book A

QUESTIONS & ANSWERS

Third Edition

Ro,Ciogrophic Testing Method ,"'.. tevels l, ll ond lll Review euestions - Book A ''.-";.,'.. "".. aL

ta., t".,.a-,.

The Americon Society for ' Nondestructive Testino, Inc.

copyright

@ 2014

by The Americon Society for Nondestructive Testing.

The Americon society for Nondestructive Testing.,lnc. (ASNT) is not responsible for the herein Published

outhenticity or occurocy of inforn-: opinions ond stotements do not necessoriiy retr.ciiir. opinion of ASNT. products or services thot ore o: or mentioned do not corry the endorsement or recommendotion of ASNT. No port of lhis publicotion moy be reproduced or tronsmitled in ony form, by meons elecironic or mechonicol includjno or othe'*ise' wiihout the expressed prior written permission of The Rmerton iocietv for Nondesrruci, t??lJ,i;Littrding IRRsP' NDr Hondbook' rhe NDr Technicion ond www'osnt.org lnc' ACCP' ASNI Leve/ ltl study Guide, Moteriols Evoluotion, ore trodemorks of The Americon society for Nondeslructive itonaesrrucilve resling Hondbook,Reseorch ln Nondeslructi, Evoluotion ond RNDE ore regisiered trodemorks of The Americo;i;;i.l;

for Nondestructive Testing, Inc.

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Printed in the United Stotes of Americo Published by:

The.Americon Society for Nondestructive Tesiing, lnc. l7l I Arlingote Lone Columbus, OH 43228-OSi 8 www.osnt.org Edited by: Cynthio M. Leemon, Educotionol Moieriols Supervisor

Assisied by: Bob Conklin, Educotionoi rr,toieriols Ediior

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Monoger of publicotions

ASNT Mission Stotemeni: ASNT exists to creote o sofer

ii

world by promoting the profession ond technologies of nondestructive lestino.

:

a ffiffiffiffiffiffi Acknowledgments lnlroduction .. . References level l-ReviewQuestions Answers level ll- ReviewQuestions Answers Level lll- Review Questions Answers FigureSources

.. ...iv .. ... ...v

... ...vi .....1 .....10

.........1I . .

...

.25

.... . .. .27 .

.. ..54

........55

,

rf il

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The American Society for Nondestructive Testing, Inc. is grateful for the volunteer contributions, technical expertise, knowledge and dedication of the following individuals who have helped make this work possible.

Technicol Reviewers

- FMC Technologies Galip Buyukyildirim - Kuzguncuk Mah Icadiye Cad Chinam Dwarikanath Patra - PSL Limited Claudia Kropas-Hughes - Air Force Trey Gordon - Boeing Scott McCldn - US Arm1., Picatinny Arsenal David Savoy - Versa Integrity Group Bahman Zoofan - Amerapex Corporation Edward i. Briggs

Publicotion Review Commitlee Glenn M. Light, Chair - Southwest Research Institute Martin T. Anderson - Alaska Technical Training Joseph L. Mackin

iv

-

Reel Group

o Kffiffiffiffie#ffiKKffiru Purpose This book was previously published as Supplement to Recommended Practice SNT-TC--IA (QdvA Book): Radiographic Testing. This is an update of previous editions prepared by members of ASNT's Penetrating Radiation Committee. As with other books in the ASNT Questions & Answers series, this book is intended to provide candidates studying for qualifying examinations with sample Level I, II, and III questions. The questions are similar to the types of questions one might encounter on a certification examination and should be used for review and for practice examinations only. Though this book is intended to cover the body of knowledge in ANSI/ASNT CP-105: ASNT Standard Topical Outlines for Qualification of Nondestructive Testing Personnel (2011), it is not intended to comprehensively cover all possible technical issues that may appear on a certification exam.

Whot ls New The main changes between the second and third editions are that the references have been updated, many questions have been updated, and every question is multiple choice with four unique answers to more closely match the ASNT exam format.

Additionol Informotion Because ASNT is an International System of Units (SI) publisher, throughout the text both SI and imperial units are used. Level I and Level II questions use imperial units first. Level III questions use SI units first. For simplicity, many equations in this book use 25 mm equals 1 in. Where SI units are not used in the original text of a standard or code, conversions to SI

units were not made. All figures are from ASNT sources unless otherwise indicated.

Recommended References

Reference G

The follou,ing references u,ere used in formulating the questions contained in this book.

Becker, WT. and R.]. Shipteir Metals Handbook,ninth edi_ tion, rVorudeslructive Inspection and euality Control, \rolume 1

Reference A

1. Metals Park,

OH: American Societl, for Nttetals. 2002.

Bossi, R.H., F.A. Iddings, and G.C. Wheeler, tech. ecls., p.O. Moore, ed., Nondestructite Testing Handbook, third edition:

Additionol References

4, Radiographic Testing. Columbus, OH: American Society for Nondestructive Testing, Inc. 2002.

The follor,ving references are listed it Cp- j05-20 j1 as recommencled references but rvere not used in building this book. These references may be useful for additional study oi the radiographic testing method.

\blume

Reference

B

Staton. l. Radiographic Testing Classroom Training Book (PTP Series). Columbus, OH: American Societl, for Nondestructive Testing, Inc. 2005.

Reference C ASNT Level

III

Study Guide: Radiographic Testirtg Methort.

Columbus, OH: Anterican Society for Nondestructive Testing, Inc. 2014.

Reference

D

McCain, D., ASNT Study Guide: Industrial Radiography Radiatiorr Safety. Colttmbus, OH: American Society for Nondestructive Testing, Inc. 2009.

Reference

E

'

Radiographl, in Modern Industry, fourth edition. Rochester, NY Eastman Kodak Co. http://wr,r,rv.kodak.com/eknec/ documents/87/0900688a802b3c87/Racliography-in-

Modern-h-rdustrv.pdf. 1 980.

Reference

F

Annual Book of ASTM Standards, \rolume 03.03. Nondestructiye Testing. "standard Guide fbr Radiographic Examinationi' Standard ASTM E 94, and "stanclard practice for Design, Nlanufacture, and _Nlaterial Grouping Classification of Hole-Type Image euality Indicators (Iei) Used for Radiologyi' Standard ASTN,i E 1025. philadelphia, PA: American Society for Testing and Nlaterials. l.atest edition. (Reference numbers alier the questions contain

Materials and Processes for ND'l' Tbclmology. Columbus, OH: American Society lor Nondestructive Testing, inc. i981. McGuire, S.A. and C.A. Peabody. Working Safely in Radiography. Columbus, OH: American Society for Nondestructive Testing, Inc. 2004.

(

Mix,

P.E. Introduction to Nondestructive Testing: A Training Guide, second edition. New york: /ohn Wiley & Sons. 2005.

Nondestructive Eyaluation and euality Control: ASM Handbook, Voiume 17. Metals park, OH: ASM

International.

1

989.

Schneerr-ran, l.G. Industri al X-ray Interpretation Evanston, IL: Intex Publishing Co. 1985.

Taylor, ].L., ecl., Basic Metallurgy Jbr l'{on-Destructiye Testing, revised edition. Essex, England: WH. Houldershaw, Ltd. (Britlsh Institute of Nondestructive Testing). 19gg. Thielsch, H. Defects and Failures in pressure Vessels and Piping. Nerv lbrk R.E. Krieger publishing. 1977. W'elding Inspection Handbook. Miami, FL: American

Welding Society. Latesr edition.

the standard number. Example: F.E94.)

a L

D

Reference Codes Each question in this book is followed by letter(s) and page number(s) indicating the specific recommended reference where the answer may be found. For example:

7.

Co-60 used in nondeslructive testing emits:

iffi$tstlii:.:ia;}:i:*::ilriiiri*

. :, ..::,tir,.:::at,rfdlt!..a.':l: g,rAaut!a,ar5. ::ilil*.:i!i::,alf $::$ii:f:il# ,lilf "''

'.i.11,.:i1i$.,,,,.

:.::,::,t,,

:.'. :':),,.1: tt:,| r:,ii:,r:r,_:l .r lli:i|:..1:::,li :i:r.!::

,,

'

.":

'Si*$if$ffi

In this example, the letter'A' refers to Reference A in the list above and 44,74-75 arc the specific pages in Reference A where the answer to the question is located.

Reference Usoge ReferenceATolol =210 Level Level Level

I (48) II (80)

III

Reference D Toiol = Level Level Level

11

I (5) II (0)

III

(6)

,I!tys.i,l,:',ii:i::i::,1]::ri*],r:ll,,r,;ai:.jii:llii:it:::,ilr::l:r:::,::iiir1:ri'i'i:j.ii;i

il;:A; ii::i::jiiij:,+ri.rii:if!f.:ii,.*ili a:.:: .::.

ReferenceClolol =33 I (5) II (5) III (23)

Level Level Level

(82)

ReferenceETolol =168 Level Level Level

I (38)

II (34) III (96)

ReferenceFTolol =15 Level Level Level

I (3) II (3)

III

(9)

ReferenceGTolol =5 Level Level Level

I (0) II (5) III (0)

ReferenceBTotol =27 Level Level Level

I (6) II (8) III (13)

) vil

,

I,.

fl:j'iu,,'{' i;,,;,,,i,,,,, ,ji,

Review Questions Although there may be other reasons for using calcium tungstate screens in industrial radiography, they are most often used to:

5.

a. 0.5 in. (12.7 mm) b. 0.002 in. (0.051 mm) c. 0.005 in. (0.127 mm) d. 0.010 in. (0.254 mm)

a. improve definition and resolution in radiographic images.

b. improve contrast in radiographic images. c. decrease exposure time. d. make fiims respond to multimillion volt

r

radiation.

6.

t 2.

,;

An excellent radiograph is obtained under given conditions of exposure with the film located at a distance of 36 in. (914.4 mm) from the target of the X-ray tube. If the film ls now placed only 18 in. (457.2 mm) from the target, and all exposure

& 1d? 7.

4.44

ime' E

*.

8.

An excellent radiograph is obtained under given exposure conditions with a tube current of 5 mA and an exposure time of 12 min. If other conditions are

a. 24 min b. 12 min c. 6 min 4.

3

.f{.1 *,$

9.

[.{? In film radiography, image quallty indicators (IQIs) are usually placed:

I

Three liquids which are essential to process an exposed film properly are:

a. stop bath, acetic acid, and water. b. developer, stop bath, and HrO2. c. deveioper, fixer, and water. d. acetic acid, fixer, and stop bath.

min

a. between the intensifying screen and the film. b. on the source side ofthe test object. c. on the film side ofthe test object. d. between the operator and the radiation source.

?4 7i

A densitometer is an instrumerit for measuring:

a. X-ray intensity. b. film density. c. density of a material. d. tube current.

not changed, what exposure time would be required if the X-ray tube current could be raised to 10 mA?

d

Co-60 used in nondestructive testing emits:

a. alpha particles. b. neutrons. c. gamma rays. d. X-rays.

a. unchanged. b. longer by approximately 80%. c. shorter by approximately 55%. d. only about 25% as long as the original exposure J.

ilfl:5

The penetrating ability of an X-ray beam is governed by:

a. kilovoltage. b. time. c. milliamperage. d. source-to-film distance

conditions except time are held constant, the new exposure time will be:

I

When radiographing to the 2-2T quality level, an ASTM IQI for 0.5 in. (12.7 mm) thick 2024 aluminum alioy has a thickness of:

10.

The two most common causes for excessively high-density radiographs are:

a. insufficient washing and overdevelopment. b. contaminated fixer and insufficient washing. c. overexposure and contaminated fixer. d. overexposure and overdevelopment. A.141,243 1

11.

t7.

The time required for one-half of the atoms in a particular sample of radioactive material to disintegrate is called:

applied to the entire body in a short period of time?

*.?.1: lj. i * &.d3

18.

What does R/h refer to?

When doing gamma-ray radiography with high-intensity emitters, the sources are best handled:

a. directly by personnel

a. Radiation limits for humans. b. Roentgen per hour. c. X-rays per hour. d. Radiation in hYdrogen.

b.

c.

D"83 13.

d.

19.

a. b.

17*

The term used to exPress the number of curies (becquerels) ofradioactivity per ounce or gram of

permanentlY.

d. 20.

uneven development or streaking could occur'

The selection of the proper type of film to be used for the X-ray examination of a particular part depends on:

A"4S$

a. the thickness ofthe Part. b. the material of the sPecimen. c. the voltage range of the available X-ray machine' d. quality of radiograph or exposure time'

a. curie (becquerel). b. roentgen (sievert). c. half-life.

n ya

d' Mev'

2L.

A.Br. q2

may have a cumulative effect which must be considered. u'iIl be beneficial since they build up an

a

half-life of:

,9'?4

immunitY to radiation Poisoning.

c. will have no effect on human beings' d. will have only a short-term effect on human

A Co-60 source has

a. 1.2 years. b. 6 months. c. 5.27 years. d. 74.3 days.

Exposure to X-raYs or gamma raYS:

tissues.

condition over the

r"8).1*l:

The unit of measurement used for the output of a gamma-ray source is the:

b.

the radiograph may not show proper contrast' it will be impossible to fix the radiograph

entire radiograPh'

a. decay. b. emissivitY. c. specific activitY. d. source outPut.

a.

is placed in a developer solution and allowed

.. th... will be a general fogglng

source weight is:

16.

If a film

to develop without anY agitation: 4.',! 51.

15.

by the same methods used for low-intensity emitters. p,.s{J

a. contrast. b. sensitivity. c. density. d. resolution. t4.

equipped with special

protective clothing' by remote handling equiPment. directly by personnel with special protective clothing except when radiographs are being made.

The ability to detect a small detail is called radiographic:

22.

I t

a. 0-25 R (0-250 mSv). b. 25-100 R (250-1000 mSv). c. 400-600 R (4000-6000 mSv). d. 600 R or more (6000 mSv or more)'

a. the inverse square law. b. a curie. c. a half-life. d. the exposure time. t2.

if

Which dose would be most dangerous, if not fatal,

X-ray tube current is controlled by the:

a. current passing through the filament' b. distance from the cathode to the anode' c. type of material used in the target' d. voltage and waveform applied to the X-ray tube' 3.;11; {.1.i.}

Review Questions

23.

28.

Lead tbil in direct contact with X-rav film:

a. intensifies

the scatter radiation more than the

primary radiation.

b. c. d.

decreases the contrast

ofthe radiographic

Primary radiation that strikes a film holder or cassette through a thin portion of the specimen causes scattering into the shador.r,s of the adjacent thicker portions, producing an effbct called:

image.

a. radiatjon imaging. b. spotting. c. undercut. d. unsharpness.

intensifies the primary radiation more than the scatter radiation. should not be used when gamma rays are emitted by the source ofradiation.

i.:

1^

Lead intensifying screens are usually mounted in pairs in rigid holders called:

29

a. primary scattering. b. undercut. c. reflectedscattering. d. backscattered radiation.

In order to decrease geometric unsharpness: 30.

b.

c. d.

should proceed from as small a focal spot as other considerations u.ill aliom radiation should proceed from as large a focal spot as other considerations u.ill allow. the film should be as fhr as possible from the object being radiographed. the distance from the anode to the material examined should be as smal1 as is practical.

Which of the following materials is suitable for use in containers used to mix processing solutions?

a. Stainless steel. b. Aluminum. c. Galvanlzed iron. d. Tln. i 'i i:4 31.

26.

Scattered radiatior.r caused by any material, such as a

or floor, on the film side of the specimen is referred to as:

a. radiation

,

Of the follou,ing, rvhich would be especially sensitive to injury by excesslve exposure to X-rays or gamma

As the kilovoltage applied to the X-ray tube ls raised:

rays?

X-rays of longer wavelength and more penetrating pol\rer are produced. X-rays of shorter tvavelength and more penetrating power are produced. c. X-rays of shorter rvavelength and less penetrating power are produced. d. X-rays oflonger rvavelength and less penetrating 32 power are produced.

a. White blood cel1s. b. Biood vessel ce1ls. c. Immature red blood cells. d. Digestive system lining cells.

a.

j.it, Film clverexposure from X-ray radiography may be caused by: a.

27.

In order to increase the intensity of X-radiation:

a. the tube current should be increased. b. the tube current should be decreased. c. the test specimen should be moved farther tiom

I

...1

u,al1

a. filrr-r racks. b. cassettes. c. emulsifiers. d. diaphragms. 25

1

the film.

d. a lower kilovoltage should

be applied to the tube.

lower kilovoltage radiations in the direct beam h-om the X-ray tube target. scatter radiation arising fron-r objects in the direct beam.

residual radiatior.r that exists for the first few minutes after the X-ray machine has been returned to the 'bff" position. d. high'speed films.

q te&-roi tno

Rodiogrophic Testing Meihod

JJ.

i

LEVEL

I

A general rule often employed for determining the

If

kilovoltage to be used when radiographing a part is

4

an exposure time of 60 s was necessary using a

that:

ft (1.2 m) source-to-film distance for a particular exposure, what time would be necessary if a 2 ft

a.

(0.6 m) source-to-film distance is used and all other variables remain the same?

the kilovoltage should be as high as other factors

will permit.

a. 120 s b. 30s

b. the kilovoltage should be as low as other factors will permit.

c. d.

the kilovoltage is alrvays a fixed value and cannot be changed. the kilovoltage is not an important variable and can be changed over a wide range without affecting the radiograph.

c.

15s

d. 240 s I 39.

a,3s

-i

'

One ofthe generai rules concerning the application of geometric principles of shadow formation to

radiography is: 34.

If

of lead 0.5 in. (12.7 mm) thick is placed in the path of a beam of radiation emanating from Co-60, it will reduce the dose rate at a given location

a.

by,

b.

a. one-third. b. one-quarter. c. one-half. d. three-quarters.

c.

a piece

d. &.1

35.

l;.?3-:3

offilm to light prior to development of the film wiil most likely result in: Excessive exposure

a. b. c.

a foggy film.

d.

yellow stain.

40.

improveddefinition.

a. a reference plate. b. a lead screen. c. an image quality indicator d. an illuminator.

:.i:

Reticulation resulting in a puckered or net-like film surface is probably caused by: a.

I

As a check on the adequacy ofthe radiographic technique, it is customary to place a standard test piece on the source side of the specimen. This standard test piece is called:

streaks.

.: i ;J. 36.

3;

the X-rays should proceed from as large a focal spot as other considerations will allow the film should be as far as possible from the object being radiographed. the distance between the anode and the material examined should always be as great as possible. as far as the shape of the specimen will allow, the plane of the maximum interest should be perpendicular to the plane of the film.

crimping film after

exposure.

(IQI).

, :,r? :l41.

sudden extreme temperature change while processing in the developer. c. water or developer on unprocessed film.

An IQI is used to indicate the:

b.

d.

a. size of discontinuities in a part. b. density of the film. c. amount of film contrast. d. sensitivity ofthe radiographic technique.

excessive object-to-fi1m distance. .*..t44

fr.?* J/.

Frilling or loosening of the emulsion from the base of the film is most likely caused by:

42.

a. water or developer on unprocessed film. b. Iow temperature of processing solutions. c. developer solution contamination. d. warm or exhausted fixer solution.

A fluorescent intensifying screen will: a.

b. c.

F

tn?

emit light that may lessen the necessary exposure. result in reticulation. decrease the graininess of the image when using gamma rays. increase the definition in a

i:.**,

4

I

radiograph. !**

Review Questions

The three main steps in processing a radiograph are:

{)43

48.

a. developing, frilling, and fixation. b. developing, fixation, and washing. c. exposure, developing, and fixation. d. developing, reticulating, and fixation.

developer is to:

a. disperse unexposed

b. prevent frilling. c. dislodge any air bubbles clinging to the emulsion. d. secure uniformity of development over the whole

Kilovoltage, exposure time, and source-to-film distance are three of the most important X-ray exposure factors that can be controlled. A fourth such exposure factor is:

a. focal point size. b. temperature. c. filament-to-focalspotdistance. d. miiliamperage.

area of the fiim. ,&.:*$ 49.

When the minute silver grains on which the X-ray film image is formed group together in relatively large masses, they produce a visual impression called:

The activity ofthe developer solution is stabilized by:

a. constantly agitating it. b. heating processing solutions. c. avoiding contamination from d. adding replenisher.

A.1$* 45.

silver grains on the film

surface.

A.::* 44.

When manually processing films, the purpose for abruptly tapping the hangers against the side ofthe tank after the films have been lowered into the

the wash bath. &.14?

50.

The purpose of fixation is:

a. to carry away and diffuse fixer from the film. b. to leave the developed silver as a Permanent

a. air bells. b. graininess. c. reticulation. d. frilling.

image.

c. to deactivate the develoPment. d. to transform the exposed silver halide crystal

to

metallic crystal. 46.

Static marks, which are black tree-iike or circuiar marks on a radiograph, are often caused by:

,q.?:s 51.

a.

film being bent when inserted in a cassette or

Water spots on films can be minimizedby:

a. the rapid drying of wet fiim. b. using a wetting agent solution. c. using a fresh fker solution. d. cascading water during the rinse cycle.

holder.

b. foreign material or dirt embedded in screens. c. scratches on lead foil screens. d. improper film handling techniques.

&

4/.

The purpose of agitating an X-ray fiim during development is to:

a. b.

protect the film from excessive pressure. renew the developer at the surface of the film.

c.

disperse unexposed silver grains on the film surface.

d.

preventreticulation.

52.

1114

The small area in the X-ray tube from which the radiation emanates is called the:

a. diaphragm. b. focal spot. c. focusing cup. d. cathode. A.S*

Rodiogrophic Testing Method

53.

i

LEVEL

I

The radiation quality of a gamma-ray source is:

58.

a. determined by the size of the focai spot. b. determined by the isotope involved. c. varied by the operator. d. greater inlr-192 than in Co-60.

The exposure ofpersonnel to X-radiation and gamma radiation can be measured by means of:

a. geiger-miiller counters. b. radiationdetectors. c. ionizationchambers. d. thermoluminescent dosimeters

*.i4

(TLDs).

*.ts 54.

The radiation intensity of a radioisotope: 59.

a. increases with time. b. decreases with time. c. is not affected as time elapses. d. increases with tube current mA.

Assuming that a good radiograph is obtained at a setting of 10 mA in 40 s, how much time would be necessary to obtain one equivalent radiograph ifthe milliamperage is changed to 5 mA (all other conditions remaining constant)?

a.

55.

a. 37 B<1 b. 37 GBq c. 37 000 000 TBq d. 3 700 000

*.;i7 60.

e 56.

3*

a. a bar chart. b. an exposure chart. c. a characteristic curve. d. a logarithmic chart.

a given exposure time and kilovoltage, properly exposed radiograph is obtained with

a 6 mA min exposure at the distance of 20 in. (508 mm). It is desired to increase the sharpness of detail in the image by increasing the source-to-film distance to 40 in. (1016 mm). The

8.51

correct exposure to obtain the desired radiographic density at the increased distance is:

61.

cailed:

a. a bar chart. b. an exposure chart. c. a characteristic curve. d. a logarithmic chart.

Fd?

Very short wavelength electromagnetic radiation produced when electrons travelling at high speeds coliide with matter is called:

a. X-radiation. b. beta radiation. c. gamma radiation. d. alpha radiation.

A graph that expresses the relationship between the logarithm ofthe exposure applied to a photographic material and the resulting photographic density is

a. 12 mA-min b. 24 mA-min c. 3 mA-min d. 1.7 mA min 57.

A graph showing the reiation between material thickness, kilovoltage, and exposure is called:

3',I

With a

20s

b. 10s c. 80s d. 160 s

A curie is the equivalent of:

I53 62.

Short waveiength electromagnetic radiation produced during the disintegration of nuclei of radioactive substances is called:

a. X-radiation. b. gamma radiation. c. scatter radiation. d. backscatterradiation.

I

Review Questions

63.

A photographic image recorded by the passage of X-rays or gamma rays through a specimen onto a

film

68.

Fluoroscopy differs from radiography in that:

a.

is called a(n):

fluoroscopy uses a much lower kilovoltage than radiography.

a. b. c. d.

b. fluoroscopy is much more sensitive than

fluoroscopic image. radiograph. isotopicreproduction. photofluorograph.

c. d.

r.?

radiography. the X-ray image is observed visually on a fluorescent screen rather than recorded on a film. fluoroscopy permits examination of thicker parts

than does 64.

radiograPhY'

In order to achieve uniformity of development over

r.r*r

the area of an X-ray film during manual processing: 69.

a.

b.

c. d.

the film should be placed in a dryer after being developed. the developer should be agitated by using mechanical stirrers or circulating pumps. the film should be agitated while in the developer. the film should be transferred directly from the developer to the fixer.

An advantage of the pocket dosimeter Qpe of ionization chamber used to monitor radiation received by personnel is:

a. it provides

begi

I

nn

i

ng of the shift.

When referring to a 2T or 4T hole in the ASTM IQI, the T refers to the:

s.r* 70.

a. b. c. d.

part thickness.

The density difference between two seiected portions

of a radiograph is known

as:

plaque thickness.

a. unsharpness. b. radiographiccontrast. c. specific activity. d. subject density.

time of exposure. time for developing. A 45S rr$5

66

permanent record of accumulated

b. it provides an immediate indication of dosage. c. it is the most sensitive detector available. d. it should be charged and set to zero prior to the

r.r*? 65.

a

dosage.

A sheet of lead with an opening cut in the shape of the part to be radiographed may be used to decrease the effect ofscattered radiation, which undercuts the specimen. Such a device is called a:

&.]s* 71.

a. mask. b. filter. c. backscatter absorber. d. lead foil screen.

X-rays, gamma rays, and alpha particles all have one thing in common; they are all:

a. particulateradiations. b. electromagnetic radiations. c. microwaveradiations. d. ionizingradiations. 8.5:

67.

Two X-ray machines operating at the same nominai kilovoltage and milliamperage settings:

will produce the same intensities and qualities

o1

radiation.

will produce the

same intensities but may produce different qualities of radiation. will produce the same qualities but may produce different intensities of radiation. d. may give not only different intensities but also different qualities of radiation.

b.

&..1S6

a.7u 0;q 72.

When producing radiographs, if the kilovoltage is increased, the:

a. subject contrast decreases. b. film contrast decreases. c. subject contrast increases. d. film contrast increases.

Rodiogrophic Testing Melhod

73.

I

LEVEL

I

The accidental movement of the specimen or film during exposure or the use ofa focus-film distance that is too small will:

78.

a. neutrons. h. electrons. c. positrons. d. protons.

a. produce a radiograph with poor contrast, b. make it impossible to detect large discontinuities. c. result in unsharpness ofthe radiograph. d. result in a fogged radiograph. ti. I r"it:

74.

e..1,)

79.

The velocity of all electromagnetic radiation is:

a.

Lead screens in intimate contact with the film during exposure:

b. a.

b. c. d.

reduce exposure time and improve radiographic quality. absorb the shorter wavelength scattered radiation more than the long wavelength primary radiation. intensi$, the photographic effect ofthe scatter radiation more than that of the primary radiation. cause film overexposure. ,$..

75.

l

s?

c. d.

80.

Unexposed boxes of X-ray film should be stored:

a. flat. b. on edge or end. c. in a pile. d. in any arrangement. &

81. .&.':

7l:

The iead symbol B is attached to the back of holder to determine:

r,r'ou1d

the unshieided dosage rate be at 30 ft (9 mX

a. 300 mRih (3000 pSv/h) b. 600 mR/h (6000 pSv/h)

c.

100 mR/h (1000

d. 2700 mR/h

77.

pSv/h)

(27 000 prSv/h)

Which has the shortest wavelength?

a. Visible light. b. Microwaves.

c.

?* I

th. filrn

a. sensitivity. b. whether excessive backscatter is present. c. radiographiccontrast. d. density.

An unshlelded isotope source gives a dosage rate of 900 mR/h at 10 ft (9000 pSv/h at 3 m). What

186 000 miles per second (299 338 km per second). 18 600 miles per second (29 934 km per second). 186 000 miles per minute (299 338 km per minute). i860 miles per second (2993 km per second). *."6?3

The sharpness of the outline in the image of the radiograph is a measure of:

a. subject contrast. b. radiographic definition. c. radiographiccontrast. d. film contrast.

76.

t

Beta particles are:

r.fr94

82.

Image quality indicators for _ are considered Group I Materials and do not need to have an identification notch.

a. high-temperature nickel-chromium b. nickel c. stainless steel d. aluminum bronze

alloy

100 kV peak X-rays.

d. Infrared

radiation.

( B

Review Questions

83.

The reason a shim is used in a radiographic setup is to:

The purpose ofa dated decay curve is to:

a. determine the source size at any time. b. calculateshieldingrequirements. c. determine the source strength (activity)

a. improve the IQI image. b. reduce diffraction. c. simulate weld thickness. d. intensify the image.

at any

time.

d. mark the date and Iength of time for each exposure.

&.4$* 89.

84.

Why is Co-60 used as a radiation source for medium-weight metals of thickness ranges from 1.5 to 9 in. (38.1 to 228.6 mm)?

a. b.

The density of a radiograph image refers to the:

a. thickness of the lilm. b. thickness of the specimen. c. weight of the film. d. degree of film blackening.

Because of its short haitllife. Because of the limited amount of shieiding

li.'*q

required.

c. Because of its penetrating ability. d. Because of its weight and ease of handling.

.

90.

::"

:1

a. Photoelectricabsorption. b. Compton effect. c. Pair production. d. Rayleighscattering.

The cause for poor image definition could be:

a. too short source-to-film distance. b. screens and film in close contact. c. fine grain film. d. smaller source sizelefTective focal spot.

&,?: L.'il

;:r,

86.

Which of the following is nof a common method of absorption of X-radiation and gamma radiation during their interaction with matter?

91.

During manual film processing, the purpose of the

The image of the appropriate IQI and hole on the radiograph indicates that the radiograph has the required:

stop bath is to:

a.

a. contrast. b. definition. c. sensitivity. d. Iatitude.

change the exposed silver salts to black metallic silver.

b.

neutralize the developer and stop the developing

* *T

process.

c. d. remove all of the undeveloped

eliminate most water spots and streaks. 92.

siiver salt of the

The primary parts of an atom are:

emulsion.

a. proton, neutrino, and electron. b. proton, electron, and gamma ray, c. photon, electron, and neutron. d. proton, electron, and neutron.

[..iS

87.

A thin, metallic sheet (brass, copper, lead, etc.) placed at the soutce to reduce the effects of softer radiation is known as:

a. an intensifying screen. b. a filter. c. an electron inducer. d. a focusing cup.

93.

A.1Si}.l il;:

l.

e.1

X-rays and gamma rays travel in:

a. pairs. b. orbital spheres. c. straight lines. d. curved lines.

Rodiogrophic Testing Method

I

LEVEL

I 98.

A large source size can be compensated for by:

94.

a. increasing the source-to-specimen distance. b. adding iead screens. c. increasing the specimen-to-film distance. d. increasing the penumbra. S.14 S?"1*lir;

machine output?

a. Rectifier. b. Cathode X-raY tubes. c. Gas X-raY tube. d. Vacuum X-raY tube.

*.3t''3f

Radiation arising directly from the target of an X-ray tube or an accelerator, or from a radioactive source, is usually referred to as:

95.

What is sometimes used to change the alternating current from a high-voltage transformer to direct current for the purpose of increasing the X-ray

*.1t"13

99.

object is governed bY:

a. secondary radiation. b. primary radiation. c. backscatter. d. inherent radiation.

a. source-to-filmdistance. b. time. c. kilovoltage. d. milliamperage.

&.s*s To produce X-rays, electrons are accelerated to a high velocity by an electrical field and then suddenly stopped by a coilision with a solid bodl'. This body is

96.

In X-radiography, the ability to penetrate the test

*.3*

ca1led a:

types of radiation is emitted by Co-60 and used in nondestructive testing?

a. cathode. b. filament. c. target. d. generator.

a. Neutrons. b. Gamma rays. c. X-rays. d. Alpha particles. e..$.s,

material has

\ A.44

$t

The best X-ray efficiency is produced rvhen the target

97.

100. Which of the following

101.

a:

The term used to describe the loss ofexcess energy by the nucleus of radioactive atoms is called:

a. decay (disintegration). b. ionization. c. scintillation. d. activation.

low atomic number. b. high atomic number. c. low hardness. d. high hardness.

Ansyvers,,,.,

tg: ., ,r.,1f,

,fr^,.

,L6r,.

2$4r,, 3os, 4?ib..:,44d 57rd':.,:r'58dr:

',77d

,','7Za;

,e5i. 'a6b, 99c:rr lOOb

10

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.i

'ita

'4b, 18b

.5d

,6a:'.

t7,i.,

10d,

t1c

!2b

13b,,t,r ,t,:::X4e:

a!,Cll

21e

8b 22a

r'ga'.

20d

23C,

z4b

!:bia,,

26h,

21ai, ;: :,',?BC'

,34c

35a

36b

a;7d

3,Sc

39c,

4Oe

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4!,d,

50d

51b'

,;52'b,,

53b

54b

5$P,',1, , ;:'lr;,56b

'64c

65b

66a

6,7d

79d, :93e'

80b

eib

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95b

68e AZc 96c

83C,:r. 'r.,',84c g7b:, t. rr:.r,- o8e

31d:

32d

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46d

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59c,: 73c,,..

87b 101a

6Orb

74a 88c

.

Lr:

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63b ' I'I IC. i.

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erd

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r,,.

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I

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LffiWffiil

KK

Review Questions

1.

Low-voltage X-ray tubes are generally fitted with windows made of:

5.

A Co-60 gamma-ray source has an approximate practical thickness limit of:

a. plastic. b. beryllium. c. glass. d. lead.

a. 2.5 in. (63.5 mm) of steel or its equivalent. b. 4 in. (101.6 mm) of steel or its equivaient. c. B in. (203.2 mm) of steel or its equivalent. d. 11 in. (279.4 mm) of steel or its equivalent. A.*?-*3: S.3**

2.

tr3

&?il

The projected area ofthe target ofan X-ray tube is called the:

The absorption of gamma rays from a given source when passing through matter depends on:

a. focal spot. b. focus. c. effective focal spot. d. geometricunsharpness.

a.

b. c. d.

r..*

The general rnethod of producing X-rays involves the sudden deceieration ofhigh-velocity electrons in a solid body called a:

a. focus cup. b. filament. c. target. d. cathode. A"*t

If it were necessary to radiograph

the atomic number, density, and thickness of the matter. Young s modulus value of the matter. Poissont ratio value of the matter. the specific activity value of the source.

" . : 7.

,,,

The fact that gases, when bombarded by radiation, ionize and become electricallv conductive makes them useful in:

a. X-ray transformers. b. X-ray tubes. c. masks. d. radiation detection equipment. s,.?*

in. (177.8 mm) thick steel product, which of the following gamma-ray sources wouid most likely be a7

The velocity ofeiectrons striking the target in an X-ray tube is a function of the:

used?

a. atomic number of the cathode material. b. atomic number of the filament material. c. voltage difference between the cathode and

a. Co-60 b. Tm-170 c. k-192 d. Cs-137

anode.

d. current flow in the rectifier l{./{}"13

circuit. e t1

5' t1

Rodiogrophic Testing Method

I

LEVEL

II

The uneven distribution of developed grains r,vithin the emulsion of a processed X-ray film causes the subjective impression of:

13.

a. graininess. b. streaks. c. spots. d. white scum.

The gamma ray intensity at I ft (300 mm) from a 1 Ci (37 GBq) source of radioactive Co-60 is nearest to:

a. 15 R per hour (i50 mSv per hour). b. 1000 R per hour (10 000 mSv per hour). c. 1 R per min (10 mSv per min). d. 10 mR per day (100 pSv per day). 4.172

Nofe: lf queslions similor lo 10 or

I'l

ore used on o

fesl,

&.4*-4$ 14.

lhe exominee should be furnished wilh semilogorilhmic coordinole poper.

10.

b.

Co-60 is reported to have a half-life of5.3 years. By how much should exposure time be increased (over that used initially to produce excellent radiographs

No change in exposure time is needed. Exposure time should be about 119/o longer. C. Exposure time should be about 37o/olonger. d. Exposure time should be about 620/o to lO0o/o longer.

The focal spot in an X-ray tube:

a.

c.

when the Co-60 source was new) when the source is 2 years old?

d.

is inclined at an angle of 30o from normal to the tube axis. is maintained at a high negative voltage during operations. should be as large as possible to ensure a narrow beam of primary radiation. should be as small as possible without unduly shortening the life of the tube.

a.

fr.13-14

b.

15.

ld. :::i;*

A source of h-192, whose half-life is 75 days, provides an optimum exposure of a given test object today in a period of 20 min. Five months from now what exposure time would be required for the same radiographic density, under similar exposure

&.&* 16.

a. 10 min b. 20 min d. 6h

e.:r$

a.

The quantity of radiation that will produce, by means ofionization, 1 electrostatic unit ofelectricity in 0.001293 g of dry air is known as a:

a. millicurie. b. gamma. c. roentgen. d. curie.

c. t h and 20 min

Of the following, the source providing the most penetrating radiation is:

(

X-ray transformer.

conditions?

t2.

In an X-ray tube, the filament and focusing cup are the two essential parts of the:

a. anode.

*,i4 11

I

A.3',' -33

17.

The specific activity of an isotopic source is usually measured in:

Co-60.

b. 220 kVp X-ray tube. c. 15 MeV X-ray betatron. d electrons from Ir-192.

a. million electronvolts (MeV). b. curies per gram (Ci/g) [becquerel per gram 4.74.-7&; G"3S7

c.

(eq/g)1. roentgen per hour (R/h) lcoulomb per kilogram

(c/kg)1.

d. counts per minute (cp-). &..4$S: 8.37; e"?'[

12

I

Review Questions

i8.

Which of the following isotopes has the longest

/.7.

half-life?

a. Tm-170 b. Co-60 c. h-192 d. Cs-137 A

An X-ray tube with a small focal spot is considered better than one with a large focal spot when it is desired to obtain:

a. greater penetrating power. b. better definition. c. less contrast. d. greater film density.

,"{ '7

r.1? 19.

The primary form of energy conversion when electrons strike a target in an X-ray tube results in the

24.

One method of reducing radiographic contrast is to:

production of:

a. a. primary X-rays. b. secondary X-rays. c. short wavelength X-rays. d. heat.

b.

film.

c. d.

I35.f1: 20.

increase the distance between the radiation source and the object. decrease the distance between the obiect and the decrease the wavelength ofthe radiation used.

increase development time within manufacturer's recommendations.

The slope of a straight line joining two points of specified densities on a characteristic curve of a film is known as the:

*.?& 25.

Thin sheets of lead foil in intimate contact with X-ray

film during exposure

a. speed ofthe curve. b. latitude. c. average gradient. d. density. 2r.

a.

b. c.

a. poor definition. b. low contrast. c. high speed. d. high average gradient.

26.

emit electrons when exposed to X-radiation and gamma radiation, which help darken the fi1m.

X-ray tubes are often enclosed in a shockproofcasing in order to:

a. b.

The purpose for circulating oil in some types of X-ray tubes is to:

c. d.

a. lubricate moving parts. b. absorb secondary radiation. d.

fluoresce and emit visible light, which helps expose the film. absorb the scattered radiation. prevent backscattered radiation from fogging the

Ji.l'4

r l.{

decrease the need for high current. dissipate heat.

because

film.

An X-ray film having wide latitude also has:

c.

film density

they:

d.

22.

increase

dissipate heat.

protect the operator from high-voltage shock. shieid the tube from secondary radiation. increase the efficiency ofthe rectifier. A.**

27.

The slope of the characteristic curve of a radiographic film is called:

a. speed. b. latitude. c. gradient. d. density.

ld

A.2Zs4

r3

Rodiogrophic lesting Mefhod

28.

i

LFVEL

II

In X-ray radiography, alternating currellt must be changed to pulsating direct current in order to satisfy the need for unidirectional cr.rrrent. This change mav be accomplished by:

a. b. c. d.

32.

The adjustment of tube current in conventional X-ray tube circuits is made by:

a. adjusting the current supplied to the filament. b. adjusting the target-to-cathode distance. c. inserting resistance in the anode lead. d. opening the shutter on the X-ray tube port.

transformers. rectifiers. anodes. cathodes.

' s. 12

t

JJ.

E,

J.I

In comparison with lower-voltage radiographs, high-energy radiographs show:

29.

When radiographing to the 2-2T quality level, an ASTM IQI for 2.5 in. (63.5 mm) steel has a

a. greater contrast. b. greater latitude. c. greater amounts

thickness of:

a. b. c. d.

0.5 in. (12.7 mrn) 0.0025 in. (0.064 mm) 0.005 in. (0.127 mm)

d.

,

a.

(76.2 mm) steel casting using an exposure time of 10 min and a source-to-tilm distance of 36 in.

b.

(914.4 mm). If

it

is necessary to change tl.re sor"rrce-to-film distance to 24 in. (609.6 mm), what

exposure time u,ould produce a sirnilar radiograph all other conditions remain the same? 1.6

. .::

Filters used at the port of the X-ray tube:

A good Co-60 radiograph is made on a 3 in.

a.

greater gradient.

0.05 in. (1.27 mm)

34. 30.

of scatter radiation relative to

primary beam intensity.

c. if d.

intensify the X-ray beam by contributing secondary radiation. filter short wavelength X-ray beams to provide sofier radiation. provide the most readily adjusted means of moditying X- ray intensit1,,. filter out soft radiation to provide a more homogeneous X-ray beam.

min

t fi.li*

b. 4.4 min c. 6.4 min d. 8.8 min

35.

.-::

An ASTM IQI fbr use when inspecting a 0.5 in. (12.7 mm) thick steel plate to the 2-2T quality level using a 16 in. (406.4 mm) source-to-film distance rvould be made of:

31.

When sharp, black, bird-foot shaped marks, rvhich are known not to correspond u,ith any discontinuities, appear at random on radiographs, they are probably caused by:

a. prolonged development in o1d developer. b. exposure of the film by natural cosmic ray

c. d.

showers during storage. static charges caused by friction.

a. 0.005 in. (0.127 mm) thick aluminum. b. 0.05 itt. (1.27 mm) thick aluminum or steel. c. 0.01 in. (0.254 mm) thick steel. d. 0.002 in. (0.051 mm) strip of any metallic material. i:.ll?4. r3*35

inadequate rinsing after fixing.

I 14

Review Questions

36.

Filters placed between the X-ray tube and specimen tend to reduce scatter radiation, undercutting the specimen by:

a. absorbing b.

c. d.

the primary beam. absorbing the shorter wavelength components of the primary beam. absorbing backscatter radiation. decreasing the intensity of the beam. *94.

directly proportional to the size ofthe focal spot and inversely proportional to the source-to-object distance.

c. 3

d.

Besides serving as a filter, screens of high atomic numbers, such as lead and lead antimony, also:

inversely proportional to the object-to-fi1m distance and directly proportional to the source-to-object distance. inversely proportional to the size ofthe focal spot and the object-to-film distance.

*.:y'" :.j4 i..l*

",:,-1

distance needed for a

proper radiograph.

4t.

The range ofthickness over which densities are obtained that are satisfactory for interpretation is a measure of the:

Images of discontinuities close to the source side of the specimen become less clearly defined as:

-:a'd';':i 42.

a. subject contrast ofa radiograph. b. sensitivity of a radiograph. c. latitude ofa radiograph. d. definition of a radiograph.

X-ray films with large grain size:

a.

b. ,1 150

1" Jr;

a. source-to-object distance increases. b. the thickness of the specimen increases. c. the size ofthe focal spot decreases. d. the thickness of the specimen decreases.

E.J3

:$l

c.

Almost all gamma radiography is performed with:

a. natural isotopes. b. 1r-192, Co-60, or Cs-137. c. radium. d. Tm-170.

directly proportional to the object-to-film distance and inversely proportional to the size of the focal spot.

b.

b. provide some image intensifying action. c. permit the use of higher speed film. d. decrease the graininess in a radiograph.

39.

a

radiograph is:

a.

a. decrease the source-to-film

38.

The amount of unsharpness or blurring of

the longer wavelength components of

F

37.

40

d.

produce radiographs with better definition than film with small grain size. have slower speeds than those with a relativelr'small grain size. have higher speeds than those with a relatively smail grain size. take longer to expose properiy than film with relatively small grain size.

tirll 43.

'i

7X

As the effective energy ofthe radiation increases:

a. film graininess increases. b. film graininess decreases. c. radiographic definition increases. d. film speed decreases. 44.

\

The half-life of radioactive Cs-137 is nearest to:

a. 36 days. b. 6 years. c. 30 years. d. 526 days.

,/

t5

l-

Rodiogrophic Testing Method

45.

I

LEVEL

II

The most commonly used target material in an X-ray tube is:

a. b. c.

49.

t

A gas-filled region located in an electrical field created by electrodes across which a potential difference is applied forms the major portion of:

copper.

a. a low-voltage X-ray tube. b. a megger. c. a hot cathode X-ray tube. d. an ionization chamber.

carbon. carbide.

d' tungsten' ;tr:-

&.e

46.

The purpose for including a disk-shaped target that rotates rapidly during operation in some X-ray tubes is to:

a. b.

50.

a.

of radiation.

fluoroscopic screens. c.

method.

combination of magnet and transformer designed to guide and accelerate electrons in a circular orbit to very high energies is a

s xsl

5i.

called:

cost and slow speed.

d. the need tbr using long wavelength X-rays and the lack of X-ray intensity associated with this

&.*l A device that is basically

Two serious obstacles to high-intensity fluoroscopy

the inabiiity to reproduce results and the need for periodic replacement of screens. b. the limited brightness and iarge grain size of

increase the intensity of X-radiation. decrease the voltage needed for a specific quality

c. increase the permissible load. d. decrease the intensity of X-radiation. 47.

1

a. an electrostatic belt generator. b. a linear accelerator. c. a betatron. d. a toroidal electromagnetic tlpe X-ray tube.

In generai, the quality of fluoroscopic equipment is best determined by:

a. densitometer readings. b. IQI sensitivity measurements. c. discontinuityareameasurements. d. reterence standards.

&..**

A.;.;;' 48.

Two isotropic soLlrces of a given strength have two different specific activity values. The source with the higher specific activity value will:

a.

b. c. d.

16

have a smaller physical size than the source with a

lower specific actir.,ity have a shorter half-life than the source with a lower specific activity. produce harder gamma rays than the source with a lower specific activity. have a iarger physical size than the source with the lower specific activity.

52.

In fluoroscoplc testing,

a

fundamental difficulty is

the relative 1ow brightness level of the images. One method lor lnereasins briehtness Lrses that converts light energy from the initial phosphor surface to electrons, r'l'hich are in turn accelerated and focused onto a smaller fluorescent screen.

a. a betatron b. an electron amplifier c. an image amplifier or intensifier d. an electrostatic belt generator

Review Questions

A general rule governing the application ofthe

!,s3

58.

geometric principles of shadow formation states that the:

a.

b. c. d.

54.

X-rays should proceed from as large a focal spot as other considerations will a1lon. distance between the radiation source and the material examined should be as small as practical. film should be as far as possible from the object being radiographed. central ray should be as nearly perpendicular to the film as possible to preserve spatial relationships.

a. to act as an intensilying screen. b. to protect the film from backscatter radiation. c. to support the holders and cassettes. d. not for specific use. &.155

A lead sheet containing

a pinhole may be placed halfway between the X-ray tube and the film in order to:

The der.eloper solution is:

b.

determine the approximate size of the focal spot. measure the intensity of the central ray.

c.

filter scatter radiation.

a.

a. acidic. b. alkaline. c. saline. d. colloidal.

d. soften the X-radiation. *.26 ,i. ]

55.

X-rav exposure holders and cassettes often incorporate a sheet of lead foil in the back, which is not in intimate contact with the film. The purpose of this sheet of lead foil is:

In certain cases, it may be advantageous to pack lead

l^':

shot around a specimen. The purpose for doing this is to:

The radiographic absorption of a material will tend to become less dependent upon the composition of the material when:

c.

preYent movement of the specimen. increase the subject contrast. generate smaller wavelength X-radiation

d.

decrease the effect ofscattered radiation

a.

b.

[,

a. the kllovoitage is increased. b. the source-to-fihn distance is decreased. c. the kilovoltage is decreased. d. a filter is used.

undercutting the specimen. d\.I 55 &.1

$}

6t. 56.

The formula (milliamperes x time) + distance2 is:

a. used to calculate fllm gradient. b. the reciprocity 1aw. c. used to determine radiographic contrast. d. the exposure factor.

a.

b.

".'t. 57.

The capacity that can be handled by an X-ray tube focal spot is governed by: a.

b.

When performing radiography on steel with thickness less than 1 in. (25.4 mm):

the composition of the cathode. the size ofthe focal spot and the efficiency ofthe

c.

a

Co-60 would give greater radiographic sensitivity than a 250 kV X-ray machine. a 250 kV X-ray machine would give greater radiographic sensitivity than Co-60. the use offluorescent screens would result in a radiograph of better quality than would lead foil screens.

d.

the use of lead foil screens wili require a shorter exposure time than will fluorescent screens.

4.7*

cooling system ofthe anode. the distance frorn the anode to the cathode. d. the high-voltage wavetbrm. c.

. " f :::

)d 17

Rodiogrophic Testing Method

62.

j

LEVEL

II

A radiograph made with an exposure of 12 mA minutes has a density of 0.8 in the region of maximum interest. It is desired to increase the density to 2.0 in this area. By reference to a characteristic curve of the film, it is found that the

66.

a. independent of the tlpe of film used. b. independent of the quality of X-radiation

difference in log E, between a density of 0.g and 2.0, is 0.76. The antilogarithm of log 0.76 is 5.8. What must the new exposure time be to produce a radiograph with a density of 2.0?

a. b.

c. d.

primariiy determined by the subjec

radiation is changed.

67.

A.]*&"id*

$:

The intervai between the time a film is placed in a fixer solution and the time when the original diffuse, yellow milkiness disappears is known as:

a. clearing time. b. fixing time. c. hardening time. d. oxidation time.

The absorption of radiation by a material varies:

a. directly with the square of the distance from

&

or

gamma radiation. drastically changed when the quality of X-ray

*.

9.12 mA minutes 21.12 mA minutes

c. 69.6 mA minutes d. 16 mA minutes oJ.

For practical purposes, the shape ofthe characteristic curve of an X-ray film is:

the

source.

b.

fi,;11

c.

with the thickness of the material. inversely with the amount of scattering in the

d.

material. in an approximately exponential manner with the thickness of the material.

68.

film and lead foil screens, and graininess possible causes of:

The photoelectric effect involves:

a. b.

c.

the visible electromagnetic spectrum. an electric camera. complete absorption of a photon.

d.

photodisintegration.

In order for

a

radiograph to have an

69.

"

!**. 17*"'trl

A radiograph of a steei weidment is made using

IeI

such mottling is:

sensitivity of

a. incorrect exposure time. b. excessive object-to-film distance. c. failure to use a lead screen during exposure. d. excessive exposure to ultraviolet rays.

the radiographic procedure has to be able to differentiate a 2o/o difference in specimen thickness.

b. the radiographic procedure c. d.

a

MeV betatron. When the radiograph is developed, there is an overall film mottling. A possible cause for 15

2-2T or better:

a.

are

t &.1"trs. !5f

,&.4*

65.

offilm

a. high fiim density. b. poor definition. c. fogged film. d. low film density.

&.s7. : s3 64.

Improper geometric factors, poor contact between

must be able to define the 2T hoie in an IQI that is 2a/o of the thickness of the specimen. the radiograph must be abie to distinguish a discontinuity with a length equivalent to 2o/o of the specimen thickness. all the holes on the IQI must be seen on the radiograph. t\.ttt

r&-

7n

A basic difference between a radiograph and fluoroscopic image is:

a

a. the fluoroscopic image is more sensitive. b. the fluoroscopic image is a positive whereas

c. d.

15t

the

radiograph is a negative transparency. the fluoroscopic image is brighter. negligible. r.16'l

r8

t

Review Questions

Ir7'

A

1000 kVp X ray machine used in conjunction with lead fbil screen has an approximate practical thickness limit of:

75.

a

The most important factor for determinir.rg the amount of X-rav absorption of a specimen ls the:

a. thickness of the specimen. b. density of the specimen. c. atomic nature of the materlal. d. Youngt modulus of the material.

a. 1.5 in. (38.1 mm) of steel or its equivalent. b. 3 in. (76.2 mm) of steel or its equivalent. c. 5 in. (127 mm) of steel or its equivalent. d. 16 in. (406.4 mm) of steel or its equivalent.

i .:l i;.ili 76

72.

Because ofgeometric factors such as source size,

source-to-specimen distance, and specimen-to-film distance, there can be a lack ofperfect sharpness at the edges ofindications. The unsharpness caused by geometrical factors may be referred to as the:

a. b. c. d.

The approximate radiographic equivalent thctors for steel and copper at 220 kV are 1.0 ar-rd 1.4 respectively. Ifit is desirable to radiograph a 0.5 in. (12.7 mm) plate of copper, what thickness of steel would require about the same exposure characteristics?

a. 0.7 in. (17.8 mrn) of steel. b. 0.35 in. (8.9 mm) of steel.

astigmatic effect.

penumbral shadorv. focus variation. geometrlcal noise.

c.

1.4

d.

1.0

in. (35.6 mm) of steeI. in. (25.4 mm) of steel.

r' ': i:l

,: ia

IJ

Two factors r,vhich greatiy affect the suitability of the target material in an X-ray tube are: a.

b.

77.

commonly used to adjust subject contrast?

tensile strength and yield strength. melting point and magnetic strength.

Source-to-film distance. lvlilliamperage. c. Kilovoltage. d. Focal point size. b.

c. electrical resistance and tensile strength. d. atomic number and melting point.

t. 74.

b.

c. d.

,r,

ll

Fllms that are left between lead screens too long in high-temperature and high-humldity atmosphere

a

lr.)

The reason the exposure time must be increased by a factor of lbur rvhen the source-to-film distance is doubled is that:

a.

Which of the follorving technique variables is most

the intensity of radiation decreases at an exponential rate rvhen the source-to-film distance is increased, the quality ofradiation is inversely proportionai to the square root ofthe distance from the source to the film. the intensity of radiation is inversely proportional to the square ofthe distance from the source to the film. the scattered radiation effect is greater as the source-to- filn distance increases. S."?4S-147; 8.18: e.5

78.

l

may:

a. b. c. d.

show increased speed but decreased qualitv characteristics. become fogged. become mottled. show tree-shaped iight areas in the finished radiograph. &.1 i;1

79.

The quantitative measure of film biackening is referred to as:

a. b.

definltion. photographic density.

c.

film contrast.

d. radiographic contrast.

l 19

Rodiogrophic Testing Melhod

80.

i

LEVEL

II

A curve that relates density with the logarithm of

85.

The slope (steepness) ofa characteristic curve is

exposure or of relative exposure is calied:

measure of:

a. a sensitivity curve. b. a density-exposure curve. c. a characteristic curve. d. an X-ray intensity curve.

a. subject contrast. b, radiographic delinition. c. radiographiccontrast. d. film contrast. &.; s7

81.

Subject contrast is nof affected by:

a. thickness differences b. radiation quality. c. scatteredradiation. d. film size.

r.s9 86.

a. fluoroscopy. b. xeroradiography. c. stereo radiography. d. parallel radiography.

Which of the foilowing instruments would exhibit the best sensitivity and most likely be used to detect small leaks in a radiation barrier?

a. A film badge. b. A fountain-pen-type c. A geiger counter. d. A dosimeter.

q

87.

ionization chamber.

A.?S 83.

At voltages above 400 kV the use oflead to provide protection may present serious problems. If this is a serious problem, which of the following materials would most like1y be used as a substitute?

a. b. c. d.

"&

Steel. 88.

3:

A qualitative term often used to indicate the size of the smallest detail that can be seen in a radiograph is:

a. radiographicsensitivity. b. radiographicdefinition. c. radiographiccontrast. d. subject contrast.

rgrS

iocation.

Concrete. Boron.

4:i

The depth of a discontinuity can be estimated by making two exposures on a singie film from two different positions of the X-ray tube. The depth of the discontinuity is computed from the shift in the shadow of the discontinuity with respect to the images of fixed markers on the front and back of the specimen. The method is called:

a. stereo radiography. b. xeroradiography. c. fluoroscopy. d. the parallax method of depth

Aluminum.

&.1

84.

A special radiographic method requiring two radiographs taken during separate exposures from two different positions to give the visual impression of a three-dimensionai display when viewed in an optical device simultaneously is called:

in the specimen.

*,.13S-1f1 82.

L

a

i:e

,*?

Agitation of the developer during the development process may:

a. b. c.

speed the developing cycle. help replenish the developer. cause undesirable, preferential flow ofdeveloper aiong certain paths.

d.

cause

reticuiation.

A t?l)

t 20

Review Questions

89.

The activity of the fixer diminishes after being used

for

a

94.

a. it results in comparatively b. it results in comparatively

a. active ingredients evaporate. b. active ingredients are absorbed by the radiograph. c. fixer solution accumulates solubie silver salts. d. active ingredients settle to the bottom ofthe tank. & 90.

A distinctive characteristic of high-voltage radiography is that:

period of time because the:

c.

^]: I i:'

d.

high subject contrast. high radiographic

contrast. is applicable to comparatively thick or highly absorbing specimens. there is no contrast in high-voltage radiography.

it

In processing radiographs, the hourly flow of water in the wash tank should be:

"i ":i

95.

a. 2-3 times the volume of the tank. b. 4-8 times the voiume of the tank. c. at least 40 gal (151.4 L) per hour. d. varied continuously in proportion to the number

using:

a. lhe fluoroscopic technique. b. low-voltage radiography. c. high-voltage radiography. d. xeroradiography.

of radiographs being developed. f;.

Lead screens are used for almost all exposures vnhen

il:

s..; 91

The equation for determining geometric unsharpness Us is UsiF = dlDo. Which change below will decrease the geometric unsharpness?

96.

s?

*{}

I

Which of the following glasses would most likely be used as an X-ray barrier window on fluoroscopic equipment?

a. b. c. d.

I

Source-to-object distance decreases. Object-to-film distance increases. Size

a. Heat-resistantglass. b. Lead glass. c. Optical glass. d. Barium oxide glass.

of radiation source decreases.

Thickness of test specimen decreases. .q.14$

92.

i: 97.

a.

significantly decrease the average gradient of

c. d.

a. b. c. d.

increase the average gradient of a

characteristic curve. increase the slope of a characteristic curve. have little effect on the shape of a characteristic curve.

A"ild-r:s As the development time increases:

a.

b. c. d.

Radiographic undercutting is caused by:

a

characteristic curve.

b. significantly

93.

ltl

Increasing the X-ray or gamma-ray energy will:

the characteristic curve grows steeper and moves to the left. the characteristic curve grows steeper and moves to the right. the characteristic curve remains the same in shape but moves to the left. there is little effect on the characteristic curve.

side scatter.

poor geometry. lead screens. free electrons. r-Iil

98.

When other operating conditions are held constant, change in tube current causes a change in radiation intensity emitted from an X-ray tube, the intensity being approximately proportional to tube current. What is the primary factor that prevents this from being exactly proportional?

a. b. c. d.

a

The voltage and voltage waveform of an X-ray machine transformer vary with load. Wavelength changes are not exactly proportional. Current cannot be changed at a linear rate. Scatter radiation does not vary at a proportional rate.

I 21

Rodiogrophic Testing Method

99.

i

II

LEVEL

When viewing a radiograph, an image of the back of the cassette superimposed on the image of the specimen is noted. This is most likely due to:

t04

a.

b. ,&.t

$3.

t a;4

c.

The half-value layer of lead for Co-60 is approximately 0.5 in. (12.7 mm). If the radiation level on the source side of a 1.5 in. (38.1 mm) lead plate is 64 R/h (640 mSv/h), the radiation level on the opposite side is:

a. b.

c. d.

d.

105.

8 R/h (80 mSv/h) 21.33 R/h (213 mSv/h) 10.66 R/h (106 mSv/h) 32 R/h (320 mSv/h)

Which of the followi ng is not

The 40 kV exposure rvould have a lower contrast and a greater latitude than the 50 kV exposure. The 40 kV exposure would have a higher contrast and a greater latitude than the 50 kV exposure. The 50 kV exposure would have a lower contrast and a greater latitude than the 40 kV exposure. The 50 kV exposure would have a higher contrast and a greater iatitude than the 40 kV exposure. ?..

A 250 kVp X-ray machine used in conjunction with lead foil screen has an approximate practical

a

factor in determining

r ]f;

a. The nature of the specimen. b. The radiation quality used. c. The type of film used. d. Intensity and distribution ofthe

106.

a. specific activity ofthe source. b. quality ofthe source. c. atomic weight of the source. d. half-life ofthe source.

scattered

&.t7s

If an exposure time of 60 s and a source-to-film distance of 4 ft (1.22 m) is necessary for a particular exposure, what exposure time would be needed for an equivalent exposure ifthe source-to-film distance

ft

[.]$ t07

increases the generation ofshort wavelength

X-rays.

a.27s

b.

c.

135

s

d.

400

s

c.

decreases the generation ofshort rvavelength X-rays. improves the radiographic quality by decreasing

d.

offers no improvement in radiographic quality.

scatter radiation. A"XS7

tr_4S

Developer solution should be discarded when the quantity of replenisher added equals:

108

Film seiection for an X-ray exposure does not depend on:

a. the original quantity ofdeveloper. b. 2-3 times the original quantity of developer. c. 5-6 times the original quantity of developer. d. 10 times the original quantity of developer. r.t

22

In million-volt radiography, filtration at the tube:

a.

(1.83 m)?

b. 49s

103

The degree ofconcentration ofthe radioactive a gamma-ray source is referred to as the:

material in

radiation.

is changed to 6

a

a. 1.5 in. (38.1 mm) of steel or its equivalent. b. 2.0 in. (50.8 mm) of steel or its equivalent. c. 6.0 in. (152.4 mm) of steel or its equivalent. d. 7.5 in. (190 mm) of steel or its equivalent.

subject contrast?

r02.

-."

*1)

thickness limit of:

A.Sl 101.

is radiographed at 40 kV and again at 50 kV with time compensation to give the

radiographs the same density, which of the foliowing statements would be true?

a. undercut. b. overexposure. c. the X-ray intensity was too high. d. backscatter. 100.

If a specimen

l*

a. the thickness ofthe part. b. the material of the specimen. c. the voltage range of the X-ray machine. d. radiation absorption in the air.

t

Review Questions

109. While

using an X-ray tube for radiography, the operator wants to increase the radiation intensity. To do so, the:

a. b. c.

i

13.

a. Source activity, tlpe of fiim, type of screens. b. Source activity, size of film, thickness of rnaterial. c. Source size, source activity, specimen-to-fi1m

kilovoitage should be lowered. tube current should be increased. test specimen should be moved farther from the

d.

tube current should be decreased.

distance. Source size, source side of object-to-film distance, required geometric unsharpness.

," .1:'r'

A.3* 1

10. Lead screens are put in direct contact with the

ll4.

film to:

a. limit the photographic action on the film. b. absorb the shorter wavelength scattered radiation. c. intensify the photographic effect of the primary d.

1.

a. porosity. b. slag inclusion. c. tungslen inclusion. d. inadequate buildup.

more than the scattered radiation. protect the film from poor handling.

The main purpose of the X-ray generator controls on the equipment is to:

a.

maintain the direction and width of the X-ray

b.

beam. enable the operator to obtain the intensity, quality, and duration ofexposure desired.

c.

allow the operator to adjust film focal distance remotely.

d.

change alternating current to increase X-ray

A.?**

115. A larger

physical size source may produce an equivalent quality radiograph if:

a. the source-to-film distance is increased. b. more backing lead is used. c. a faster film is used. d. exposure time is decreased. s .3 :4

116. A light image of a backing

intensity.

!:i

B on a processed

radiograph is probably caused by: ,4. i41

a. b. c. d.

112. When X-rays,

gamma rays, light, or electrons strike the photographic emulsion, a change takes place in the silver halide crystals. This change is called:

a. b. c. d.

..f.;

On a radiograph of a pipe weld, there is a very light irregularly shaped small image in the u'eld. This image would most likely be due to the presence of:

ts.119 11

be

considered in selecting a source-to-film distance?

film.

d.

With respect to quality, what three factors must

excessive density. backscatter.

kilovoltage set too low. poor film handling. r.fr?4

photographicdensity. photographic sensitivity.

117.

latent image.

Co-59 becomes Co-60 when it is placed in a nuclear reactor where it captures:

characteristiccurve. &.t4s

a. an electron. b. a neutron. c. a proton. d. contamination.

23

1:':r:-t:'

Rodiogrophic Testing Method

i

LEVEL

II

118. When

a faster speed film is substituted for a slower one to improve the economics of the exposure, which of the following conditions occurs?

The range of specimen thicknesses that can be adequately recorded on the radiograph is called:

I

a. sensitivity ofthe radiograph. b. iatitude ofthe radiograph. c. accuracy ofthe radiograph.

a. The film must receive special processing. b. The definition will improve. c. The image resolution r.vill be reduced. d. It will have no effect on the radiograph.

d'

intensitY of the

source' s.i*,!

li.{st

119.

122.

123. Approximately

how long u,ould it take for a 10 Ci (370 GBq) Co-60 source to decay to 2.5 Ci (93 GBq)?

For a given change in the radiation exposure, film contrast is the inherent abiiity to show:

a. 5.3 years b. /.9 \'ears

a. a difference in densitv. b. no graininess. c. graininess. d. no appreciable change in density.

c.

10.6 years

d.

15.9 years .ir. ,r.jj

*,.4,r

120.

124. An exposure technique

is established to obtain a 2.0 density using type D film and automatic processing at 81 "F (27 'C). In order to obtain comparable results using manual processing at 68 'F (20 .C) and 5-min development time, it rvould be necessary for the original exposure time to be:

The ability of a material to block or partially block the passage of X-rays and gamma rays is cailed:

a. penetration. b. absolution. c. absorption. d. latitude. 1.3

121.

Source size, specimen thickness, and source-tospecimen distance are the three factors that determine the:

a. density ofthe radiograph. b. exposure ofthe radiograph. c. film size. d. unsharpness recorded on the radiograph.

I

a. reduced by approximately 30%. b. increased by approximately 99o/o. c. increased by approximateiy 302o. d. reduced by approximately 99o/o.

( A"***"?SS

Nole: The lwo chorocleristic curves of Figures I ond 2 on poge 25 moy be used in solving problem I24.

I 24

i;a.., ra.:iinncrJ quuJll?t i\vv1.rYria'r. 11,

NOTE: Using Figure 2, qnswer queslion 124.

NOTE: Using Figure 1, onswer queslion 124.

l

Exposure: 200 kVp Lead Screens Developer: 5 min at 68'F (-20 'C)

Exposure: 200 kVp Lead Screens Developer: 81 'F (27.7 "C) with 11 min Dryto-Dry Cycle 4.0

4.0

I

I 3.0

I

I

Automatic processing

I

I Y

=e. t.v o

o

?

0.5

I

/

I

1.0

0

0.5

'r/

1.0

2.5

I I

I I/"1

t.5

I I

'a 62.0

#

a

I

,/ ./

1.5 2.0

2.5

3.0

0.5

Log Relolive Exposure

3.0

Figure 2

Answeri

,

rr

Lb ), , ,-2e,, 15b,

r

29d

, ,'30n-'

,1-6cr,

',]:6; ,' ,':4a.,.

t7b ,18d,

31C,r ,

,,,,32ar,,

,

5c 19d

,,;. r33b

43a.

45d.... .:,,{$c....:. .:.:. .;47.*.

71x,,.,,:7'2b.

,74C 75i ',87d i.88C 89c

44c 57tr, rj- 58b

I

2.5

Log Relolive Exposure

Figure I

85c

'1.0 1.5 2.0

86c

99d,,:196U Lte,a ,1t4c

.59a',

:,73dr ,i

,r,

':.r60el',,r., 61h

..,r.

1O1a 'i.X02err1O3b

tisa ' Li6b'

"Lii.b,

54,.

, ,r.

,i

r'-"7d

.

',

.r

8C.

.

t2Ai:''," 21b,,:. . 22d: 34d,1 r,,r35c,, :r ,' 36a,,

48a. 49-d, r'50b' rQ2c:,:63d'I r64e 7Ea '77e ' ,i,78b,1 9Ob.r '91c 92d 1Q4c 1O5b , lQBa 118c1 119a 120c

9ar:' ' 23b ' .'.i:.

r37$ rr,.

1Oc

24a :36a

5Lb, 52c' 65b, 66b 79b I 8Oc ,93a r. , 94c 107d 108d 127d 122ti

; L2.c ' t3a 25d 26b 27c 39b 4Ob 41b 53d 54b 55a 67a' ' '6Bb' 69c ' ,81dr , 82c 1 83b 95c 96b 97a 109b 110c 1,1,1b 123c 724b '71c,,,

L4d

28b

42c 56d r70b

84a 98a

7L2c

25

l,

Review Questions

lnteroction Between Penetroting Rodiqtion ond Moller

Noture of Penetroiing Rodiolion

1.

Atoms of the same element that have different of the numbers of neutrons are called

5.

element.

A consequence ofa series ofsingle events occurring as a

radiation beam passes through material is

a

decrease in intensity. The process is called:

a. molecules b. isotopes c. isotones d. isomers

a. photoelectriceffect. b. ionization. c. absorption. d. half-valuethickness.

*,3

*.? 2.

The number of positive charges on the nucleus of an atom equals the:

6.

The number of ion pairs produced by particle per

unit path is called:

a. number of neutrons. b. atomic number. c. number of photons. d. atomic weight.

t J.

a. b. c. d.

secondaryionization. total ionization. speciflcionization. roentgen.

/, "{! !l

Unlike beta and alpha particles, neutrons have no: 7.

a. b. c. d.

charge. mass.

a. 0.025 to 0.1 MeV b. 30 to 50 MeV

spin.

half-life.

Radiation scattering increases

a. b. c. d.

Pair production occurs when electromagnetic radiation consists ofphotons in what energy range?

c.

1.02

d.

0.1 to 1.0 MeV

MeV or greater

{

as:

the energy ofthe incident radiation decreases. 8. the size ofthe radiation field decreases. the angle of scatter increases. pair production is eliminated.

.,,*.

f

..d

In the photoelectric interaction process:

a. electrons are emitted. b. characteristic X-rays are emitted. c. secondary photons are emitted. d. an electron-positron pair is produced. p.*s, L.d

! a-7

Rodiogrophic Testing Method

9.

I

LEVEL

III

The compton interaction process is characterized by:

14.

a. absence ofsecondary radiation. b. no transfer ofenergy upon interaction. c. production ofan electron_positron pair. d. partial transfer ofenergy upon colliiion. *.?i; 10.

The major component of scatter is the low_energy electromagnetic radiation produced by photons weakened in the:

r.t47

lmoging by Fluorescenl Moleriols

15.

e.d

f

16. s.t4

High-energy photons of 1.02 MeV or greater t)?icaily interact with matter by which one of the following?

In photofluorography,

emission that

:l.J[T:,,

high at the X-ray wave[ngths to be

used t

matches the wavelength sensitivity of the human eye.

b. c.

has a minimum decay time. can be viewed directly without the use of leaded

d.

matches the wavelength sensitivity of the particular image detector being used.

glass

*.$*.: *_?*; *..4

In which of the foltowing processes will some energy

ofthe interacting photon be used to dislodge the electron from the K or L shell and the remiinder used to give the electron kinetic energy?

.dS, 1 j}]

where a fluoroscopic screen is used for radiographic imaging, it is important to choose a screen that has a visible light

a.

a. Photoelectricprocess. b. Compton process. c. Pair production process. d. Thermionic process.

or mirrors.

&"*57 be

a. Photoelectricprocess. b. Compton process. c. Pair production process. d. Ionization process. A.3Si; f.1*7

28

a. direct gamma-ray exposures. b. fluorescent screen exposures. c. lead screen exposures. d. direct X-ray exposures.

The increase in radiation passing through matter due to scatter in the forward direction is called:

a. buildup. b. reduction factor. c. backscatter. d. bremsstrahlung.

13.

The bunsen-roscoe reciprocity law, which states that the developed fiim density depends only on the

product of radiation intensity times exposure duration, fails for:

*.tlt

12.

According to accepted theory, the spots at which the latent image is localized on the emulsion are local concentrations of:

a. silver sulfide. b. silver bromide. c. siiver iodide. d. silver nitrate.

e .4

a. photoelectricprocess. b. compton process. c. pair production process. d. ionization process. 11.

Film Rodiogrophy

{

Review Quesiions

t7.

L

20.

When comparing fluorescent intensi$ring screens

with lead foil screens, the primary advantage

a. b. c. d.

is:

improved image resolution. markedly increased exposure times. markedly decreased exposure times. relative insensitivity to scattered radiation. F.

18.

a. Using X-ray tubes of lower operating potential. b. Using an image tube. c. Using X-ray tubes of greater effective loading. d. Using the X-ray television system.

r?4

Fiuoroscopy of a specimen using a 140 kVp 10 mA X-ray source results in an intensity of 660 mSvimin (66 R/min) at the screen surface. Of the screen brightness values and approximate screen colors below (for the stated radiation level), which represents the most desirable screen for use in direct viewing fluoroscopy?

A fundamental difficulty of fluorescent imaging is the relatively low brightness level of the images. Electronic fluoroscopy can heip to eliminate this problem by all but which one of the follon'ing?

*. ?54

Rodiometry

21.

The roentgen is defined as the amount of:

a. b.

a.

brightness

b.

brightness

color color

c. d.

-

-

9.8 Ix (0.91 ftc);

green

-

pressure. 8.5 Ix (0.79 ftc);

c.

X- or gamma radiation that will produce 1 electrostatic unit of charge in I cmr of dry air

d.

X- or gamma radiation absorbed by

- yellow

brightness - 7 lx (0.65 ftc); color - blue brightness - 4.6lx (0.43 ftc);

color

-

radiation emitted by 1 Ci of h-1.92 at a distance of 1 m (3.3 ft). X- or gamma radiation of 0.1 prf ( 1 erg) of energy in 1 g of dry air at standard temperature and

at standard temperature and pressure.

of water at of Hg).

green

0'C

1 cm3

(32 'F) and 101 kPa (760 mm

* -:a; -'!.;

L

;1. ili2

lmoging by Electronic Devices

Generolors ond Tubes os on lnlegroled Syslem

19.

22.

Unlike other commercially available X-ray intensification systems, the direct X-ray pickup tube:

a.

b. c. d.

has quantum energy losses exceeding a factor 500. has extremely low sensitivity.

converts the X-ray image directly into an electrical signal. converts X-rays to light and light to electrical signals.

of

X-ray generators built to provide X-rays at r.en'iorr' energy levels are used in special areas in nondestructive testing. The single section X-rav tubes in these low voltage units are usually bullt u.ith thin windows of what material to permit soft X-ra1-s to emerge from the vacuum envelope?

a. Beryllium. b. Germanium. c. Selenium. d. Heat-resistant

glass. A i!4

t

f?n

u 29

Rodiogrophic Testing Method

I

LEVEL

III

NOTE: Using Figure 3, onswer queslions 23 through 27.

23.

26.

a.F

The meter that typically shows the beam current ls:

d.c

27

The timer is shown by:

a. I

The filament transformer is shorvn by:

b.H c.F d.r

a.G

b.r

c.C d.E 25.

t

b.A c.D d.H

a.B b.D c.F 11

The kilovoltage selector is shor,r'n by:

28.

The focal spot should be as small as conditions permit, in order to obtain:

The autotransformer is shown by:

a. the sharpest possible definition. b. the minimum size of the unit. c. the maximum energy density. d. the maxinrum grain size.

a.G

b.r

c.C d.E

t t/

Figure 3: Schemolic of o bqsic X-roy circuil.

30

t

Review Questions

Sources of Electrons

29.

JJ.

determines the size of the electron beam bv:

'

a. b.

c. d.

a. Field emission. b. High-frequency magnetic fie1d. c. High-frequency electrical wave. d. Acceleratingmagnets.

surrounding the emerging beam with an electronic field that repels the beam into a more Iocalized form. limiting the maximum amperage of the filament current. reducing the negative charge on the glass walls of the tube caused by secondary electrons scattered by the target. controlling the electric field between the anode and the cathode.

1.,

34.

electromagnet.

l.l

reflection from the,ur*., rn the anode ofthe

35.

tube.

b. increasing the kilovoltage. c. positive ion bombardment. d. heating a filament.

The betatron accelerates electrons by:

a. b. c. d.

radio-frequency energy. magnetic induction. use ofa nonconducting charging belt. resonating the high voltage to the frequency of the AC power. .&.,$&:

32.

In a high-voltage generator ofthe electrostatic van de graaff t1pe, by which rnethod are the particles

a. Acceleratingmagnets. b. High-frequency electrical wa','es. c. Static negative charges. d. High-frequency radio waves.

Electron Acceleroling Methods

31.

i

accelerated?

& 6+

L

't

In a linear accelerator, the electror.rs are accelerated bv which of the following?

Early X-ray tubes used a cold cathode from which electrons were released bv:

a.

r

a. High-frequencyelectricalwave. b. Acceleratingmagnets. c. Neutronbombardment. d. Changing magnetic fields of an AC

&,**

30.

In a betatron, electrons are acceierated bv rvhich of the following?

The focusing cup of the cathode in an X-ray tube

fi.'i4

36.

Flash X-ray tubes are usually designed to produce

electrons for acceleration by which or.re of the following methods?

a. Hot emission. b. Cold-cathode field emission. c. Changing magnetic field of a transformer

What method is nof used for generation of X-rays in

d.

the multimillion volt range?

primary. High-frequency electrical rvaves.

a. Electrostaticgenerator. b. Betatron. c. Linear accelerator. d. Selenium target generator. *.61

t, 3l

Rodiogrophic Testing Method i

LEVEL

III

Torget Mqteriols ond Chorocterislics

37.

Tungsten is the preferred target material for X_ray tubes used in industrial X-ray machines because it provides a double advantage. One ofthe advantages is that:

a.

41.

An important design consideration of X_ray tubes, based on the low efficiency ofX_ray production, is:

a. target angle. b. focal spot size. c. acceleratingvoltage. d. heat dissipation.

the efficiency of the tungsten material in the production of X-rays is proportionai to its atomic number.

3{.& I

b. it has a low melting point. c. the efficiency of the tungsten d.

42.

material in the production ofX-rays is inversely proportionai to its atomic number. it has a high curie point.

a suitable metal

for an X-ray tube target, a property that is

a. Atomic number. b. Melting point. c. Mass attenuation coefficient. d. Thermalconductivity.

r.7

38.

In choosing

which of the following is not normaily considered?

The efficiency of the target material in the production ofX-rays is proportional to:

*,$9

a. kilovoltage. b. spacingofelectrodes. c. atomic number. d. Avogadro's number.

lsolope Sources

43.

a. Co-60 b. Cs-137 c. Ir-192 d. Tm-170

9.7, ? I

39.

Of the isotopes iisted below, which is a fission fragment from the induced fission of Ur-235?

In choosing a suitable metal for a target material, the principai properties to be considered are all but which one of the following?

&76

a. High atomic number. b. High melting point. c. High thermal conductivity. d. High vapor pressure.

44.

associated with it? a3.ss

Equipmenl Design Considerolions

40.

Another way to alleviate the localized heating of the target is with

a. b.

a:

hooded anode.

d.

line-focus anode.

l

A.*1

32

a. Co-60 b. Tm-170 c. b-192 d. Cs-137 *.s$

rotating anode. hot anode.

c.

Because it is frequently supplied as a water_soluble compound, which of the following is considered to have an additional radiological hazard,potential

t

Review Questions

rl

45.

49.

Which one of the following radioisotope sources would be the best choice for radiography of a steel specimen 9.5 mm (0.375 in.) thick from an energy standpoint?

a. 1.17 ard 1.33 MeV b. 0.66 MeV

a. b.

d.

c. d.

c.

Co-60

Tm-i70 h-192 cf-252

50.

". ;51.

2o/o

t,

_i

.

-

a smaller isotope

60/o

a.

l%o

It suffers more from self-absorption of its own gamma radiation.

b. There is more geometric

unsharpness ln the radiograph. c. It requires more safety margin. d. It allows shorter source-to-film distances.

Generally, sources of high specific activity are more desirable because thev have seif-absorption.

a. higher b. the same c. lower d. no

52.

Which of the following is an advantage of radiography u'ith gamma rays as compared to X-rays?

!'t? ,18.

Which of the following is true for

.

source of higher specific activity?

3o/o

&.*Ir B.l:l

47.

The principal gamma rays emrtted by Ir-192 are:

a. 0.66, 0.84, and 0.91 MeV b. 0.31, 0.47,and 0.60 MeV c. 0.08, 0.05, and 0.66 MeV d. 0.15, 1.12, and 0.18 MeV

The half-life is a useful characteristic of a radioisotope. After 6 half-lives, the amount of decaying atoms is reduced to approximately what percent of the amount at the beginning?

a. b. c. d.

1.09 and 1.29 MeV i.36 and 2.75 MeV

.ri,{d,;ii

*.3* 46.

Co-60 emits gamma rays of:

Radiation output, aiso known as dosage rate or characteristic intensit,v, is usually expressed as effective output in what unit per curie?

a. The complexity of the apparatus. b. 'Ihe massi'ne size of the radiation source. c. Requires fewer safety measures. d. Independence from outside power.

a. RHM b. Rhr c. rms d. mRih *.23-2&

t, 33

Rodiogrophic Testing Method

I

LEVEL

III

Film Principles ond properties

53.

54.

Suppose a radiograph is made using film rvhose characteristic graph is shown in Figure 4. The film is exposed for 12 mA per minute and has a density of 0.8 in the area ofinterest. It is desired to increase the density to 2.0. What milliamperage per minute would

(film)is:

a. gamma and/or X-ray quantum. b. alpha particles. c. electrons. d. photon.

produce such a change?

a. l9 b. 62 c. 50 d. It is impossible

The agent that actually exposes a photographic grain

.&.;: 55.

to determine from this data.

Which of the following is governed by the source size, object-to-film distance, and source-to-obiect distance?

c.s4

a. Geometricunsharpness. b. Inherentunsharpness. c. Radiographiccontrast. d. Effective graininess. &. 3 44.

56.

,6

6 o

i

6:3

Caution should be exercised to avoid removing film too rapidly from cartons, exposure holders, or cassettes. This would help to eliminate objectionable circular or tree-like black marks caused by:

a. crimps. b. reticulation. c. static electricity. d. scratches.

z.o It

tr,4t. qs

Solid-Stote Deleciors

57.

0.5 1.0 1.5 2.0

The obtainable counting speed using a scintillation counter is limited fundamentally by the:

a. energy level ofthe incident radiation. b. intensity of the incident radiation. c. delay between electron excitation and

2.5

Log Relative Exposure

de-excitation.

d. spatial distribution of the incident

quanta.

Figure 4: Chorocleristic groph.

&.'r**

58.

The scintillations (iight photons) emitted by a radiation detection phosphor are converted to electrical pulses by:

a. a photomultiplier tube. b. an ionization chamber. c. a selenium photoelectric cell. d. a light-pulse amplifier. &.i$n

34

Review Questions

Reol-Time lmoging

Other Nonfilm Devices

59.

61.

In comparing electronic image intensifier svstems that use TV presentation with those using solid-state screens and high-sensitivity closed-circuit T\r systems, which of the following statements is talse?

a.

directly convert the received X-rays to electron scanning-beam variations. The thickness ofthe glass faceplate is recognized to prevent use at lon'er kilovoltage applications, but use at higher kilovoltages

The or.erail gain of an image lntensitier/T\r combination usually exceeds that of the screen/TV combinations. The overall resolution of the ir-rtensitier/TV combination usually exceeds that of the

b.

has never gained acceptance either, compared with

other techniques. Which of the following is nof correct for this type of system?

a.

screen/TV combination.

c.

As the area ofthe viewed screen increases for either, the overall system gain must also increase. The single-crystal scintillating screens and the fine-grain fluorescent screens have better resolution than the electronlc image intensifier tubes but much lorver light output.

d.

b. c.

.4."lii*

TV

In the past, several companies have designed TV cameras with large facepiates and phosphors that

ond OpticolSyslems

60.

A fluoroscopic system for the inspection of welds in 25.4 mm (1 in.) thick steel has the following features:

* * w m

X-ray source-to-image plane spacing of 431.8 mm (17 in.); X ray lbcal spot size of 3.8 mm (0.15 1n.); steel (weld)-to-image plane spacing of 76.2 mm (3 in.); image plane length of 228.6 mm (9 in.) in vertical scan direction of T\r system used to view image

d.

*. :!?"j

Goseous lonizotion Detectors

62.

One desirable property for a gas to be used in an ionization detector is a:

a.

plane; and

w TV system

with 525 line scan, with image fully

b. c.

focused on image tube.

During tests, it is found that this fluoroscopic system does very poorly in resolving wire image quality indicators (IQIs) and imperfections of less than 0.89 mm (0.035 in.) when they are oriented paraliel to the horizontal scan lines of the TV. Assuming that the image screen, optical system, and TV frequency response are capable of much better resolution than this, which of the following will increase the resolution of the system the most?

a.

d. b

TV scan rate to 1029 lines, rvlth an appropriate increase in frequency response. Increase the X-ray source-to-image plane spacing to 508 mm (20 in.). Decrease the steel weld-to-image plane spacing to 50.8 mm (2 in.). Change to an X-ray source having a 7.6 mm (0.3 in.) focal spot. Increase the

The quantum energy losses associated with converting the X-rays to electrical signals is improved over other systems by a factor of as much as 500 times. In comparlson to systems using image orthicons with screens or with an image intensifier system, the image presented is noisier. The extreme simplicity of this system and need for few controls or adjustments makes maintenance easier than other types of systems using intermediate conversion. The extreme sensitivity of this system allows display of 29lo IQIs over the range of 40-300 kVp.

d.

low saturation potential at which recombination of positive ions with electrons becomes negligible. low ionization potential. density approximately equivalent to the density of the chamber lvalls. density equivalent to that ofair at standard temperature and pressure.

A.?:

63.

The greatest problem that arises in the routine use of a pocket dosimeter is:

a.

its relatively flat response to radiation ofdifferent energies.

b. its inherently inconsistent sensitivity. c. electrical leakage that tends to discharge the d.

electrometer and give false high readings. negative drift caused by changes in atmospheric conditions (temperature, humidity, etc.). ;5..1

?" 1

JJ

Rodiogrophic Tesling Method

64.

LEVEL

III

As a portable radiation survey instrument, the main disadvantage of a geiger counter is its:

a.

Goging ond Conlrol Processes

69.

nonlinear response with changes in radiation

are coilimated and projected through a test item and the quantity of unabsorbed radiation is measured is

energy.

referred to

b. large size and delicate construction. c. poor sensitivity to low radiation levels. d. warm-up drift during the first few minutes of ,*..?*.

t:$

&.s7e

70.

a. gamma-ray activity. b. fast neutron activities. c. slow neutron activities. d. alpha/beta dose rates. "*,.?4-?.S

An amplifier to be used in

gaging.

instrument designed to measure high levels of radiation should have the following characteristics: a survey

j&.573

71.

a. a fast rise time and a linear response. b. a fast rise time and an exponential response. c. a slow rise time and a linear response. d. a slow rise time and an exponential response.

The two types of detectors used most commoniy in X-ray thickness gages are:

a. fluorescent screens and ionization chambers. b. proportional counters and geiger counters. c. phosphor-photomultipliers and ionization chambers.

e.t:3

67.

Generaily, the sensitivity and accuracy of thickness gaging of homogeneous materials by reflection methods is:

a. superior to transmission gaging. b. superior to fluorescence methods. c. inferior to transmission gaging. d. approximately the same as with transmission

lnstrumenlotion

66.

as:

Air-filled proportional counters are used extensively for monitoring:

d.

Which of the following detectors would be most suitable for use with a gamma- or X-ray energy

fluorescent screens and phosphor-

photomultipliers. ,&.$ljt-SfS

spectrum analyzer?

Exposure Hozords

a. An ionization detector. b. A scintillation detector.

c.

72.

A proportional detector. A.$14

Which of the following radiation measurement instruments does not employ gas detection as its operation mechanism?

a. Proportionalcounter. b. Semiconductordetector. c. Ionization chamber. d. Geiger-muilercounter. A.$7$

36

Sources of radioactive material used for radiography are required by reguiation to be leak tested at

interva\s not to exceed.l

d,. A geiger-mu\\er counter.

68.

t

a. fluorescence method. b. absorption differential method. c. attenuation buildup method. d. transmissionmethod.

operation.

65.

A system of X-ray thickness gaging in which X-rays

a. 3 months. b. 6 months.

c.

12 months.

d.

24 months.

(

Review Questions

Methods of Conlrolling Rodiotion Exposure

Operolionol ond Emergency Procedures

73.

77.

Distance is an effective means of external radiation

protection because:

Survey instruments used to monitor gamma radiation must be capable of measuring radiation in the range of:

a. b.

air absorption reduces the radiation intensity. radiation intensityvaries inversely as the square

ofthe

a. 1-2 mSv/h (100-200 mrem/h) b. 20-s00 000 pSv/h (2-s0 000 mR/h) c. 0-2000 ;rSv/h (0-200 mR/h) d. 0.02-10 mSv/h (2-1000 mrem/h)

distance.

c. X-rays and gamma rays have a finite range. d. the wavelength ofthe photons is decreased by their interaction with matter.

c.29 *.,3*

74.

78.

X-ray photons differ from gamma photons of the same energy only in their:

A radiation area refers to the perimeter of any area in which the radiation level exceeds:

a. a. b.

c. d.

.&.1t8

{:; 75.

20 pSv (2 mrems)

b. 1 mSv (100 mrems) c. 50 pSv (5 mR) d. 5 mSv (500 mrems)

biological effect. origin. interaction. ability to produce an electron.

The half-life of a radioactive substance is equal to the:

Sensitivity

79.

Radiographic sensitivity depends on the combined effects of two independent factors. One is

a. reciprocal ofthe disintegration constant. b. average iifetime of an atom in the substance. c. time required for half of the original atoms to

d.

radiographic contrast; the other is:

a. radiation quality. b. density. c. IQI image. d. definition.

disintegrate. number of atoms present divided by the rate of decay.

E.55

{-"..3

76.

A tenth-value thickness for a specific gamma source is 25.4 mm (1 in.) of iead. The radiation intensity is 5000 mSv/h (500 R/h) at 609.6 mm (24 in.) from the source. How many miilimeters (inches) of lead would be required to reduce the intensity to 50 ptSvih (5 mR/h) at 609.6 mm (24 in.)?

a. 50.8 mm (2 in.) b. 127 mm (5 in.) c. 254 mm (10 in.) d. 101.6 mm (4 in.) A t ?{

80.

Using the equation

o=1oo ^1rm x

where

0-

2o/o

x-

32 mm (1.25 in.) = section thickness to be

't-

radiographed IQI thickness 1.6 mm (0.06 in.) = hole diameter

h=

= percent equivalent IQI sensitivity

determine IQI thickness:

a. 41mm (1.6 in.) b. 0.5 mm (0.02 in.) c. 0.4 mm (0.015 in.) d. 0.8 mm (0.03 in.)

) J/

Rodiogrophic Testing Method

I

LEVEL

III

Radiographic sensitivity is:

81

86.

a. a general or qualitative term referring to the size b. c. d.

a. subject contrast. b. geometric and film graininess factors. c. film contrast. d. ambienttemperature.

of the smallest detail which can be seen on a radiograph. only a measure of the contrast properties of the

radiographic system.

term usually applied to the contrast properties of the radiographic system. a term that reflects fiim speed and contrast

Radiographic sensitivity is rof affected by:

a

87.

properties.

The IQI shouid nol be used to:

a.

discontinuities.

&.1:r*

82.

Radiographic sensitivity is totally controlled by:

b. judge the adequacy ofa radiographic exposure. c. determine the adequacy of film/screen

a. fiim and screen combinations. b. those factors that control radiographic contrast

d.

combinat ions.

88.

a. a cavity of the same diameter will be visible. b. a cat ity of half the hole diameter witl be visible. c. a cavity of the same diameter may be invisible. d. the hoie and cavity will have equal detectability. rl{.

.&.1

89.

l},:l-1.:$

&.17* The sensitivity requirement 2_2T represents:

a. IQI thickness 2x the specimen thickness with the required IQI hole 2o/o of the specimen thickness. IQI thickness 2% of specimen thickness rvith the required IQI hole 2x the IeI thickness. IQI thickness 2o/o of the specimen thickness rvith the required IQI hole 2o/o of the specimen

thickness.

d.

IQI thickness 2% of the specimen thickness \\.ith the required

IeI

hole

4o/o

of

the

IeI

thickness. 4.172

3B

Using a filter at the X-ray tube, masking to lessen the thickness range, and a multiple_filni technique

a. Iow density. b. Iow latitude. c. poor definition. d. Iow radiographic contrast.

determine the size of cracks and pores that can be detected.

c.

7*

are ways ofcorrecting:

The IQI is used to:

b.

?

a. Focal spot or source size. b. Density. c. Type ofscreen. d. Radiation quality.

b. determine the crack depths that can be detected. c. determine critical discontinuity size. d. indicate the quality ofthe radlographic technique. 85.

t

Which of the following.parameters does nof directly affect radiographic definition

The visibility of a certain image quality indicator (IQI) hole on the radiograph may mean that:

a.

A ..1? 5_17

Controsl ond Definition ,4.1:,r*

84.

judge the adequacy ofpart_to_film distance.

.

and definition.

c. kilovoitage and milliamperage. d. kilorollage and lilm processing.

83.

judge the size or establish acceptance limits of

fl.$:-$5

90.

Poor definition can be improved by doing all but which one of the following?

a. Increase source_to_film distance. b. Use a smaller physical source size. c. Change from tlass II to Class I film. d. Change from lead to fluorescent screens. A.;rid

t

Review Questions

Based on the characteristic curves of the films shown

9L

94.

in Figure 5, which film provides the highest contrast?

a.

a.X b.Y c.Z d.

Film contrast refers to:

oi

the density difference in two adjacent regions

film.

b. the steepness (slope) ofthe characteristic curve. c. the ratio of X-ray or gamma-ray intensities transmitted by two selected portlons of

Cannot be determined from the curves.

a

specimen.

d.

minimum perceptible density change. iz i: il

4.0

95.

In general, the contrast of radiographic films (except those designed for use with fluorescent screens):

a. increases

E tr

b. c.

2.0

o

o

Film X

Fitm Y

,/

d.

The graininess of all films:

a.

"/

0123

96.

Log Relollve Exposure (Exposure Time)

+

b. c. d.

b Figure 5: Choroclerislic curves.

increases as the kilovoltage is increased up to approximately 200 kV. decreases as the kilovoltage is increased. is not dependent on kilovoltage. is totally controiled by Lambertt lau'. ,ll l:;

97.

Specimens with uniform thickness and composition

by definition have:

Subject contrast depends on:

a. b. c.

remains practically unchanged for different density levels. is inversely proportional to film density.

a I7t

ru^,

92.

usable density range. decreases as the density is increased.

I

1.0

0.0

continuously with tiim density in the

a. high subject contrast. b. good definition. c. high film contrast. d. low subject contrast.

mA, source strength, distance, and film type. film-screen type. nature of the specimen, radiation quality (kV), and the intensity and distribution of the scattered

r

radiation.

d'

Lamberti

law' &.xr*

93.

Which of the following is

a

factor in radiographic

contrast?

a. Film type. b. Radiation quality. c. Degree of film develoPment. d. X-ray energy.

98

rt

The sharpness of outline in a radiographic image is called:

a. definition. b. sensitivity. c. latitude. d. contrast. A,&?

4.151; F,*?4

b 39

Rcrdiogrqphic Testing Meihod i tE\lEL ffiI

99.

Poor radiographic definition is related to:

a. b. c. d.

"d"

focal spot size. source_to_filmdistance.

Distance

poor film-screen contact. degree of film development. 100 90 80 70

60 50

ng is not a factor to be

considered to reduce geometric unsharpness?

a. Source-to-filin distance. b. Object-to_film distance. c. Source strength. d. Source size.

"t " (in )

(mm)

10

10

100

9 8 7 6

4

30-

J

. 1.0 . 0.9 . 0.8

9 8 7

5

40.

" uo" Geom6trical Unsharpness

Thickness

.0.7

6

0.6 0.5

4.

o.4

a

0.3 o.2

10

it.i.itl

101.

Pivot Line

Spot (mm)

4.r44

Geometric Foctors 100. \\.hich of the foilorvi

Focal

(in.)

Using Figure 6, detennine the geometrical unsharpness under the followiig ..r;r;;;;r. Maximun.r specimen thickness

9

8 7

6

i.:s rn_ fl.s i,

5

l,

solrrce-to film distance is 1016 mm (40 in.), and the focal spot size is 1 mm (0.04 irr.;. fir. g**.t.i.ut unsharpness is:

1.0

0.9 0.8 0.7 0.6 0.5

4.

0.4

a-

0.3

0.10 0.09 0.08 0.07 0.06 0.05

o.7 OU

0

0.04 0.03 0.02

0.010 mm (0.0004 in.) b. 0.102 mm (0.00a in.) C. 0.051 mm (0.002 in.) a.

d.

40 0. 10

0.25 mm (0.01 in.) 'lr, i,'li:

102. In the.lbllowing

equation for geometric unsharpness,

what does U, represent?

u8

0.09 0.08 0.07 0.06 0.05

0.

30

0. 0.1

0 0.

0.04 0.03

=-Ft d

0.02

a. Image size. b. Penumbra.

0.010 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002

0.001

c. Source-to_film distance. d. Specimen-to-film distance.

Figure 6: Nomogrom for solving the equolion

U = !!

10,{. Deviation from the true shape of an obiect exhibited in irs shadow i_ug. i. .oiiJr'"

as

.i.,,j,i.1.i!iit,

103

The size.of the penumbral shadorv can best be reduced by:

a. definition. b. Iatitude.

using a larger diameter :b. rrsing

source. a faster speed film.

c. contrast. d. distortion.

increasing the source_to,film distance.

: increasing d.

tl-re

specimen-to-fiim distance. B.t3

40

7

).

Review Questions

105.

Which of the following rules of shadow formation

is

109.

Geometric unsharpness (Ur) is obtainable tiom:

not true?

a. The effective b. c. d.

a. u =L '' d

focal spot or source size should be practical. The distance between the focal spot or source and the test object should be as great as practicai. The central ray should be as nearly perpendicular to the film as possible to preserve spatial relations. The test object's plane of ma-ximum interest should be perpendicular to the plane of the film. as

small

as

b.,, ' : d Fr

where

F=sourcesize d=source-to-objectdi:tance / = object-to-film distance

c. utt =u d. U =t ' Frl

ri* 106.

Given an Ir-192 source 3 mm (0.13 in.) in diameter, a geometrical unsharpness of 0.5 mm (0.02 in.), and a material thickness of 63 mm (2.5 in.), determine the

A"SS, 457 1

10.

Urd--

minimum source-to-object distance.

b.

320 mm (12.6 in.) 620 mm Qa.6 in.)

FI

if F = 3 mm (0.1 in.), t = t27 mm (5 in.), and d = 1090 mm (43 in.), U, is approximately:

4t2.7 mm (16.25 in.) d. 460 mm (18.1 in.) c.

a. 0.5 mm (0.019 in.) b. 0.7 mm (0.027 in.) c. 0.3 mrn (0.012 in.) d. 0.2 mm (0.006 in.)

fr.:d

t07.

Using the formula

Projection magnification resulting from increased object-to-film distance is also useful in reducing scatter radiation because of: a.

b. c.

111.

increasing definition. reducing physical source size. the air gap.

a.

d. macroradiography.

a combination of geometric unsharpness and

magnilication.

b. deviation from the true shape ofthe object. c. magnification minus geometric unsharpness. d. a combination of graininess, unsharpness, and

&.3*? 108.

Image distortion refers to:

Magnification and geometric unsharpness:

magnification. a.

b

are actually the same thing. can be distinguished as follor,r,s: magnification refers to the degree of enlargement, and

lnlensifying Screens

unsharpness refers to the penumbra.

ll2.

are not directly related. d. can be combined to yield total unsharpness. c.

.;":

Variation in the thickness oflead screens from 0.1 mm (0.005 in.) ro 0.2 mm (0.01 in.):

a. has very slight effect on intensification. b. has very significant effect on intensification. c. actually has no effect on intensification. d. only serves to increase geometric unsharpness.

l 41

Rodiogrophic Tesling Method

1

I

LEVEL

III

13. The bunsen-roscoe

reciprocity law states that the product of a photochemical reaction is dependent only upon the product of the radiation intensity and the duration ofexposure and is independent ofthe absolute values ofeither ofthese quantities separately. This law is invalid for which of the foilowing?

118.

process?

a. Photoelectric. b. Pair productive. c. Compton scattering. d. Ionization.

a. X-rays. b. Gamma rays. c. Fluorescentscreens.

d'

Lead foii

B.?*:

screens'

119. E.r?*

114.

The quality ofthe radiation necessary to obtain an appreciable intensification from lead screens depends upon all of the following except:

a. film type. b. kilovoltage. c. milliamperage. d. thickness and material of test obiect.

The influence of low-energy scatter from the film holder is most noticeable just inside the borders of the image. This condition is called:

r.ss

120.

115. An alloy of 69lo antimony

The difference in narrow-beam and broad-beam conditions is that:

a.

and 94o/olead should be used for screens instead ofpure lead because it

provides:

c. d.

t

narrow-beam conditions imply that only the unscattered radiation reaches the detector, while broad-beam conditions imply that both scattered and unscattered radiation reach the detector. narrow- and broad-beam conditions relate only to source size. d. both terms depend on a film and screen b.

factor.

to radiographs made with lead

screens, radiographs made using fluorescent screens would show:

a. b.

narrow-beam conditions imply that both scattered and unscattered radiation reach the detector, while broad-beam conditions impiy that only the unscattered radiation reaches the detector.

r.4 !

116. In comparison

*.4

a. inherentunsharpness. b. undercut. c. geometricunsharpness. d. mottling.

fr.{*

a. greater definition. b. less mottling effect. c. better wear resistance. d. a higher intensification

I

The major component of scatter is the low-energy rays represented by photons weakened in what

combination. &.: 33

better contrast. good definition. higher density. poor definition.

Source Foctors

l2l.

Short wavelength photons are normally used on thick sections of steel instead of long wavelength photons because:

Scqtlered Rqdiotion

ll7.

a. short wavelength

Which is generaily the greater source of scatter

b.

radiation?

a. b. c. d.

Lead foil screens. Lead backing plate. Floor or wall. The specimen under examination.

c. d. 5:*

42

photons are hard rays and have greater penetrating ability. short wavelength photons create a greater secondary radiation and help improve image contrast. long wavelength photons are hard rays and have greater penetrating ability. they both have equal penetrating abilit

:Y'

r* t

Review Questions

122. A lead sheet is usually

placed behind the fl1m cassette

to:

a. b. c. d.

intensify the film image and shorten the exposure time. prevent bending and crimping of the fi1m. reduce forward scatter and absorb unwanted radiation to prevent it from reaching the lihn. minimize radiation scattered from the floor, r'r.a11s, equipment, and other items from reaching the back of the fi1m. r,

ii

123.

Exposure charts are fairly adequate for determining exposures in the radiography of:

a. complicated structural b. uniform plate. c. step wedges. d. IQIs.

becomes lower. becomes higher. remains unaffected. increases inversely to activitl..

i: i'il;

127. A gamma-ray

exposure chart differs from an X-ra,v exposure chart in that there is no variable factor corresponding to:

:, .:i

128. An exposure chart is a graph

showing the relation between al1 &u/ which one of the tbllou,ing?

*

17

lVhen radiographing a specimen with a radiographic source, it is found that it is desirable to lengthen the source-to-fi1m distance. With the source at the new location, the amount of radiation reaching the film

a. b. c. d.

Exposure. Density. Kilovoltage. Material thickness.

- iir

will:

a. b. c. d.

Dorkroom Procedures 129. The frequency with which

vary inversely with the square ofthe distance. vary equally with the square of the distance. not change. vary inversely with the distance.

a developer solution needs replacement is dependent on the rate and densitv of films processed, but as a rule the solution should be

replaced: lr.

Xl';

a.

Exposure Curves

125. Which one of the follou,ing

items.

a. thickness. b. milliamperage. c. kilovoltage. d. film density.

The larger the activity (in becquerels or curies) and the larger (physically) the source is, the emitted gamma-ray intensity:

a. b. c. d. 124.

li,

126.

is not a specific conditlon

b.

which applies to a given exposure chart?

a. X-ray machine used. b. Film type. c. Processingconditions. d. Radiationintensitv.

c. d.

whenever the density of processed films is consistently too great. rvhen the quantity ofder.eloper replenisher used equals 2 to 3 times the original quantity of developer, or every 3 months, whichever is shorter. every 6 months. whenever the processed films show streaking due to uneven development.

't'i ":

)

"

l 43

Rodiogrophic Testing Method

130.

I

LEVEL

III 135.

In manual processing, the ideal temperature is 20 "C (68 "F). At what temperature would the chemical action be slowed, resuiting in underdevelopment?

Certain materials cause contamination and result in fog in the radiograph. Which one of the following should nof be used as a material for holding processing solutions?

a. 2l'C (70'F)

b. 16 "C (60'F) c. 32 "C (90'F) d. 30'c (86 "F) r.1

131.

a. AISI Type 316 stainless b. Enamelware. c. Aluminum. d. Plastic.

*?

The shape ofthe film characteristic curve is relatively insensitive to changes in X- or gamma-radiation quality, but is affected by changes in the:

steel.

*.7&

136.

Processing tanks should be periodicaliy cleaned and sterilized. Which of the following agents in solution

is recommended?

a. geometric factors. b. film graininess. c. subject contrast. d. degree of development.

a. Sodiumhlpochlorite. b. Acetone. c. Householddetergent. d. Hydrochloric acid (diluted).

fl.'t 3$" l 39

132.

*.s*

Light crimp marks appearing on a developed radiograph are the result of:

137.

a. static marks. b. scratches on lead foil screen. c. poor handling before exposure. d. poor handling after exposure. fi';i

133.

I

a. sulfuric. b. glacial acetic. c. muriatic. d. hydrochloric. r_tr 3

Physical damage to the film emulsion caused by sudden extreme temperature change is called:

Film Processing i38. Holding all other parameters constant, an increase in time of development of a given film will result in a

a. reticulation. b. frilling. c. blisters. d. streaks.

characteristic curve showing:

fi.*,q

Dorkroom Equipmenl ond Chemicols

134.

The most commonly used acid in preparing stop baths to arrest the development process is:

When using acid to make the stop bath mixture, the acid is added slowly to the water for which of the following reasons?

a. To produce a more uniform mixture. b. To prevent rapid oxidation resulting in a cloudv stop bath.

c.

To prevent a rapid rise

d.

temperature. To prevent the acid from spattering.

a. increased contrast and increased speed. b. increased contrast and decreased speed. c. decreased contrast and increased speed. d. decreased contrast and decreased speed. s.:s1

139. In manual

processing, if it is not possible to use a stop bath, films should be:

a. placed directly b. placed directly

ofthe solution

c. d.

44

in the fixer solution. in the fixer solution with a 1 min

reduction in development time. rinsed in running water for at least 2 min before fixing. rinsed in running water for at least 2 min with a I min reduction in development time before fixing.

t

Review Questions

140.

1ll.

The primary reason why visual (under saielight conditions) development of radiographs should be avoided is:

a. neutralize alkali from developer. b. remove undeveloped silver sa1t. c. increase density. d. harden the emulsion.

a. it ls difficuit

b.

c. d.

to discern the image \\.ith the light output provided by a safelight. the appearance ofa developed but unfixed radiograph will be different in the dried state. removal of the film from the developer u.il1 aifect

141.

*.1

115.

the development time. film type and speed affect the appearance of images when exposed to a safelight.

I

\Vetting agents are used primarily as a deterrent for:

r.t

146. Ideally after

at a relative humiditv of:

a. manual

a. 10o/o. b. 30 to 50%. c. 70 to 80o/o. d. any percentage, since relative

processing is time consuming and automatic processing produces consistency and

control.

c. d.

it is difficult to train and keep manual processing personnel. automatic processors are easier to maintain. chemical temperatures and solutions are difficult to maintain in darkrooms where manual processing is practiced.

r3

processing, radiographs should be stored

performed automatically because:

b.

;l

a. reticulation. b. changes in density. c. \{ater spots. d. fril1ing.

)ti.i

Better quality radiographs can be obtained when expertly done by manual processing rather than by automatic processing, but most processing is

The most important function of the fixer is to:

humidity is not an

important consideration. *.1 147

.

In manual processing, the

cascade method

?*

of washing

film is desirable. To be effective, the hourly flow of rvater should be:

142.

a. 1-2 times the volume of the tank. b. any amount, since the water flow rate has no

The tunction of the developer is to:

a. stop the process. b. harden the emulsion. c. recover silver. d. change exposed silver halide crystals to metallic

c. d.

bearing on film washing. 12-16 times the volume of the tank. 4-8 times the volume of the tank.

*.*3r

S

l'1*

silver. H.

143.

The best method of arresting the development process is to place the film in:

a. an acid stop bath. b. a fixer solution. c. a water rinse. d. a wetting solution.

i*s

llluminolor Requirements 148. Which of the followingis

not a requirement for illuminators used in the interpretation of radiographs?

a.

A light source ofsufficient intensity to view the area of interest of the radiograph.

b.

Sufficient masking to avoid glare from the edges

ofthe radiograph.

c. d.

A foot-operated ON-OFF switch. Diffuse the light evenly over the viewing

area.

45

Rodiogrophic Testing Melhod

149.

I

LEVEL

III

For the routine viewing of high-density film, a high-intensity illuminator with an adjustable light source should be used. Such a vierver should aliow viewing of densities at least up to _ on a

154. When reviewing film, background lighting should:

a. be virtually eliminated. b. not reflect on the film under examination. c. be carefully filtered. d. be approximately 20 1m.

characteristic cune:

a. 1.5 b. 2.s c. 4.0 d. 10.0

{.Ivt

OpticolAids 155. A stereoscope i:,

150.

rti

a.

When viewing radiographs, the film viewer should provide light of an intensity that is evenly distributed i,vith an adjustment to vary the intensity. In addition, the film viewer should have:

b. c.

a. a viewing surface at a 90o angle. b. fresh bulbs. c. a diffusing medium. d. a light green color.

d. ,dl.l .i ]

151.

To prevent damage to films, which of the following should be provided when viewing radiographs?

a. Masks or screens. b. Foot switch. c. Heat filter. d. Opal glass.

a. b.

a. about the same brightness. b. a lower brightness. c. a higher brightness. d. any brightness, since brightness

from difterent angles, enables the production of radiographs. allows accurate measurements of the shift of an image in a set of stereo radiographs made for the purpose ofparallax.

c. d.

l

the kilovoltage ofthe source ofradiation. the amount of radiation absorbed by the emulsion of the film. the scintillator detector. the autonratic processing. ,4.. | .{ I

157.

Incident light ofan inrensity of2.2 klx (200 ftc) on an area of film of 1.3 density transmits an intensity of 107.6 lx (10 ftc). What is the intensity transmitted in the area of the film measuring 2.3 density?

is not a factor in

contrast sensitivitv. 'r"7t:)

For best contrast sensitivity, the film viewing room should have lighting:

in the film being

reviewed. E.73; F.E94

46

projects the contents of a pair of stereo radiographs on a screen, giving spatial resoiution to indications in the radiographs. permits each eye to see only one of a pair of stereo radiographs. by exposing two film cassettes simultaneously

ffi.i:::l[:any

The contrast sensitivity of the human eye is greatest when the surroundings compared to the area of interest on a radiograph have:

a. as dark as possible. b. approximately 38 lm. c. approximately 70 lm. d. as light as the area of interest

is a de.,,ice that:

Judging Rodiogrophic Quolity Density 156. radiographic irnage is prirrrarily

Bockground tighting

153.

l.Il1}4

f,it4

&.i?1

152.

t

a. 53.8 Lx (5 ftc) b. s.4 Ix (0.5 ftc)

c.

10.8 Ix (1 fic)

d.

1.1

ix (0.1 ftc) A.'3 &4

a L

Review' Questions

Controst

Definiiion

158. Which of the following is independent,

163.

for most

practical purposes, ofthe rvavelength and distribution of the radiation reaching the film?

a. increased. b. decreased. c. not affected. d. decreased by a negligible amounr.

a. Subject contrast. b. Radiographiccontrast. c. Film contrast. d. Definition. r"$7

159.

L64.

The relationship between film exposure and the resulting film density of any particular filn is:

a.

b. Geometric sharpness and detjnition are increased. c. Physical source size does not affect sensitivity. d. Geometric sharpness is increased and sensitivity

f .*t

As the kilovoltage is increased, the subject contrast:

is decreased.

ll.

a. increases. b. decreases. c. remains the same. d. increases directly with E2.

165.

Radiographic image quality may be adversely affected by poor subject contrast; this may be caused by:

a. time. b. source strength. c. source distance. d. insufficient absorption differences

The image sharpness of an object is nol affected by:

ii.t1,j.

166.

When a lead screen radiograph of an object shorvs poorly defined image of the object, one course of action to correct this may be to:

iil

a

in the

a. change to a coarse-grain fi1m. b. use an X-ray tube oflarger focal spot. c. increase source-to-filmdistance. d. change to fluorescent screens.

specimen. il,*6: fl.I?d The film contrast for the specimens being radiographed may be determined from:

lir.

a. the size of film. b. the radiation quality. c. the siope of the characteristic d. wavelength of the radiation.

i,il.rl

a. the type of film. b. the tlpe of screen. c. radiation quality. d. masking.

&.t ?*

t62.

Sensitivity and geometric unsharpness are increased.

*.44:

161.

What is the effect of the sensitir-itr of a radrosrap: when the physical size of I gJntntJ .uur,( l. increased without changing anv other -\;re:u.. factors?

a. the unsharpness. b. the film contrast. c. the subject contrast. d. the source-to-film distance. 160.

By increasing the source,to-fllm distance in a gir en exposure, the image sharpness is:

ir :' . 'i

il

Artifocts

167. curve for the film. $.*7;

F.ff9*$

When using lead foil intensifying screens, a fuzz:1 radiographic image is a sign:

a. of oil or grease on the screens. b. that tin coating was used on the screens. c. ofpoor screen-to-fi1m contact. d. of foreign material betrveen the screen and the film. a...

47

Rodiogrophic Tesfing Method

168. A mottled

i

LEVEL

III 172.

radiograph is caused by:

a. removing the paper interleaving before the

Prolonged washing of film in water above 20 (68 "F) has a tendency to:

t

a. crystallize the gelatin. b. soften the gelatin. c. cause a yellow stain. d. cause the image to fade.

exPosure.

b. using tin-coated lead screens. c. X-ray diffraction effects. d. exposure geometry. r,*.i. ISr t.fiSd

fl,1 13"1 ] 3

169. During

lmoge Quolity lndicolors

the loading of a film cassette, the lead foil screens are scratched. The resulting radiograph

lvould show:

a.

'C

Given 0-

100

'lThl2

-

no change since deep scratches are related to the

film.

b. broad. fuzzl \ightlines

cottespondingto itre

rx\ere x -- rN&e\:*$\tkr\rss $rrr\es\ T = IQI thickness (inches)

scratches.

c.

defined dark lines corresponding to deep

h = essential hole diamter (inches) o = equivalent sensitivity (percent)

scratches.

d.

random film indications due to scatter caused by scratches.

173. *..&2

170.

The appearance ofcolored stains on a processed

radiograph could be caused by:

a. b.

a. b. c. d.

neutralization of the acid in the fixer solution. neutralization of the alkaline content in the fixer solution. acidification ofthe fixer solution.

I7l.

174. r

Deep scratches in lead screens result in dark lines on the radiograph. These are due to:

a.

b. c. d.

2.0o/o

l.60/o

(

78o/o

t.40/o

r.r1**s

c. d. underder.,elopment.

fi.1:

Using the formula given above, calculate the equivalent sensitivity of an ASTM #20 IeI showing the 2T hole on a 1.25 in. thick specimen.

the loss ofabsorbing characteristic ofthe lead foil, resulting in more of the X-ray source reaching the film. the scratch resulting in a greater surface area of lead, causing a larger electron emission area, which affects the exposure of the film. the air gap between the deep scratch and film. lack of emulsification. ,t.43

Using the formula given above, calculate the specimen thickness if the equivalent sensitivity is 2.60/o based on seeing the 4T hole in an ASTM #40

IQI.

a. 1.35 in. b. 3.i7 in. c. 2.56 in. d. 2.17 in. r.fr]*:s

175.

The DIN type IQI is which rype of image quality indicator?

a. A plaque tr,pe. b. A stepped t1pe. c. A rr.ire t1.pe. d. An indirect imaging type. fl.

fi

( 48

Review Quesiions

Couses ond Correclion of Unsolisfoclory

180.

Rodiogrophs

176.

Omission of the stop bath or rinsing of the filn.r

The mathematical rule of exposure that gor.erns the time-distance relation of the basic exposure

calculator is:

n.rar-

cause:

a. a. streaking of the film. b. yellow staining of the film. c. fogging of the fi1m. d. frilling of the emulsion.

b. [11fi

177

.

1t

i

c.

In automatic processing, poor drying of film can be attributed to which of the fbllowing if the drying temperature and air circulation in the drying section

d.

are found to be acceptable?

a. Underreplenishment of the fixer solution. b. Infrequent use of the processor. c. Roller alignment in the r,vash section. d. Overdevelopment.

181.

a. the fixer being too warm or exhausted. b. a sudden change ilr temperature. c. use ofa carbonate developer. d. use of fine-grained film.

182. t.il1

m (6 ft) source-to-film distance for

using a

increased scatter.

c. reduce exposure time. d. eliminate most of the undercut caused bv scatter.

particular exposure, what time would be necessary if a 0.9 m (3 ft) source-to-film distance is used and all other variables remain the same? a

.i

i83. a. 2 min b. 15s c. 4 min d. 30s

The primary function of a filter is to:

a. reduce the penetrating ability ofthe radiation. b. absorb longer wavelengths, which can produce

Exposure Colculotions 1.8

Filtering an X-ray beam ls analogous to:

a. decreasing the kilovoltage. b. increasing the kilovoltage. c. decreasing the milliamperage. d. increasing the milliamperage.

appearing flxer solution could be caused by:

179. If an exposure time of 1 min was necessary

milliamperage (M). the exposure time (O required for a given exposure is directly proportional to the milliamperage (M).

Blocking ond Fillering

[ ] i*'1r1 178. A milky

the exposure time (7) required for a gir.en exposure is directly proportional to the square of the source-to-fihn distance (D). the exposure time (T) required for a gir.en exposure is inversely proportional to the square of the source-to-film distance (D). the exposure tirne (7) required tbr a given exposure is inversely proportional to tl.re

. l::

;, t.

Which of the following materials are typically used for filtration purposes in industrial radiography at energies of 150-400 kV?

a. Aluminurnimagnesium. b. Lead/copper. c. Stainlesssteel/steel. d. Cadmium/zinc.

49

Rodiogrophic Testing Method

184. A filter in the X-ray

I

LEVEL

III 188. If the thickness

tube beam has the eftect of:

range of a specimen is too great for a single exposure, a multifilm technique may be used. If trvo films of different speeds are selected for this example, the log relative exposure range for these two films is the difference in:

a. hardening the radiation beam. b. softening the radiation beam. c. dispersing the radiation bearn. d. increasing the beam intensity. 18,5.

a.

dl

E

Scattered radiation originating in matter outside the specimen is most serious for specimens which have

b.

high absorption for X-rays. One of the most satisfactory arrangements for combining effectiveness and convenience to reduce scatter when radiographing steel is to:

the slower film.

a. cut out diaphragms from lead sheet. b. pack barium clay around the specimen. c. use a iiquid absorber. d. surround the object with copper or steel shot.

c.

1og exposure between the value at the

d.

end of the slower film and the high-density end of the faster film. 1og exposure between the value at the high-density end of the slower film and the low-density end of the faster film.

low-density

r.:?

,q,155

Multifilm Techniques

186.

log exposure between the value at the high-density end of the faster film and the low-density end of the slower film curve. 1og exposure between the vaiue at the low-density end of the faster fiim and the high-density end of

Speciol Rodiogrophic Techniques

189. A setup

by which an arrangement of prisms or eye to see but a single one of pair of radiographs is known as:

The primary purpose of using two or more films of unequai speed in the same cassette is to:

mirrors permits each

a. elimir-rate retakes due to incorrect exposure time. b. eliminate retakes due to artifacts on the film. c. cover a wide range ofthickness in one exposure. d. reduce the scatter to the total image.

a. stroboradiography. b. paraliax radiography. c. stereo radiography. d. autoradiography.

t. I 113: {.$$

187.

When two different films are selected for a multifilm technique, their speeds must be such that on their

a

r_.i'.4

190.

Select the one adtantage stereo radiographs have over films produced by the parallax method.

characteristic curves there is:

a. They permit correct spatial relation. b. They use inexpensive viewing devices. c. They do not require special reading glasses. d. They use two films.

a. some overlap on the density axis. b. no overlap on the density axis. c. some overlap on the log E axis. d. no overlap on the log E axis.

A.4l !:-

50

lY

?

Review Questions

191.

Using the parallax method for triangulation with the tilm in contact with the object and shifling the source an equal distance in trvo directions lrom lts original position for location ofa discontinuity, it is revealed that the discontinuity shift is less than half the shift of the source side marker. The discontinuity is:

a. nearer the film plane. b. nearer the source side. c. on the source-side surface. d. on the lilm-side surface.

An electron emission radiograph shor,r,s surface details only; in this regard, it is similar to:

a. a macroradiograph. b. a microradiograph. c. a photomicrograph. d. tomography. 'i t96.

The principle of electron emission radiographv is

i{

A discontinuity was found by radiography in a 76 mm (3 in.) thick weld. The source-to-fihn distance was 510 mm (20 in.). A second exposure was made with the source shifted 102 mm (4 in.) parallel to the film plane. It was noted that the discontinuity image moved 16 mm (0.625 in.) as compared with the original exposure. Determine the distance of the

a. b. c.

differential absorption. dlffraction caused by crystalline structure. differences in electron emission from an irradiated specimen, resulting from greater emission from higher atomic number materials.

d.

differences

ir-r

film density

caused by the

dillerential penetrating ability of the various energy electrons.

discontinuity above the 1iIm.

I I]il

a. 82 mm (3.2a in.) b. 32 mm (1.25 in.) c. 69 mm (2.70 in.) d. 7 mm (0.27 in.)

t97.

a. l l:t

autoradiography. stroboradiography. d. flash radiography.

structure.

[.] 198.

microradiography.

Determination of segregation of constituents in thin alloy sections. Detection of minute discontinuities. The study ofbiological sections.

b. c. d. The study ofcrystalline

Radiography performed using high-inter-rsity X,ray beams to produce a single stop-motion image or a series of sequential images of high-speed dynamic phenomena is: a.

Which one of the following is not a commonly accepted use of microradiography?

h"

193.

1.7i

based on: l:.1

192

1.9s.

i,.4

X-ray devices used in microradiographv t1pically operate at potentiais up to:

b. c.

s,,{*r t94.

a. 50 kV b. 100 kv c. 150 kV d. 200 kv

Electron radiography is primarily used for radiographl, of:

il

l,r.i

Conlrol of Diffroclion Effects

a. b. c. d.

high atomic number (Z) materials. thin metaliic specimens. rery thin nonmetallic specimens. a combination of high and low atomic number

199. A method for distinguishing mottiing and other

causes

between diffractlon

of mottling is to:

a. re-expose the film using a much lower exposure

materials.

factor. r.1&8.3S?

b.

change the angle ofincidence ofthe beam by 1-5' and re-expose.

Iower the kilovoltage and re-expose. d. re-expose without using lead screens. c.

5l

Rodiogrophic Testing Method

200.

i

LEVEL

lII

Filters and screens are devices used by radiographers to control diffraction effects. If spurious indications appear in the finished radiograph and diffraction is suspect, what technique aids or corrections can be made to the technique to eliminate suspect

204.

Of the foliowing, which gaging application is most suitable for using gamma rays?

a. Cigarette density gaging. b. Thickness gaging ofthin foils such as condenser

diffraction patterns?

a. b. c.

d.

Raise the kiiovoitage.

Lower the kilovoltage. Change the radiation center 127 mm (5 in.) from the previous location. Change the class and type of film used from t,Ype 1 to type 2.

d.

Liquid density

gage.

the image size if the object is 150 mm (6 in.) in diameter, the source-to-film distance is 910 mm (36 in.), and the source-to-object distance is 760 mm (30 in.).

a. 180 mm (7.2 in.) b. 130 mm (5 in.) c. 370 mm (14.4 in.) d. 250 mm (10 in.)

thick castings at greater than 1 MeV. thin metallic specimens with large grain size. thin metallic specimens with fine grain size. thick metallic specimens with 1ow atomic

t.t*

number (Z). f;.

202.

$*

The radiographic appearance ofdiffraction patterns is mottled and may be confused with which one of the following sets of indications?

206.

The focal spot should be as small as possible, because there is a definite relationship between the focal spot size and:

a. radiographiccontrast. b. total radiation output. c. subject contrast. d. radiographic definition.

a. Porosity or segregation. b. Oxidation or burn-through. c. Porosity or burst. d. Misruns or porosity.

F?&

fi.

Goging

203.

s*

Moleriol Processing 207. A consequence of insufficient

heat, or the presence scale on the fusion face of the weld bevel, may be:

of

In routine thickness gaging setups using gamma-ray sources, which one of the following radiation detectors is most commonly used?

a. Anthracene crystal. b. Ionization chamber. c. Sodium iodide crystal. d. Geiger-miillertube.

a. incompletepenetration. b. root concavity. c. excessive root reinforcement. d. iack of fusion. &.rts / -4?$

208. A weld

made with an excessive number of passes, or inadequate speed oftravel, could result in:

a. b. c. d.

52

$rs

!moge-Object Relolionships 205. Using geometric enlargement principles, determine

X-ray diffraction patterns appearing in a radiograph are typically observed in the radiography of:

a. b. c. d.

paPers. Paper thickness gage. ,a

t.s&

20I.

c.

root concavity. oxidation. excessive root reinforcement. incompletepenetration.

Review Quesiions Disconlinuities: Their Couses qnd Effects

214. An oval or circular

dark spot with smooth edges appearing on the radiograph would most probably be indicative of:

209. A definite

discontinuity that exists because of imperfect fusion of two streams of metal that have converged is:

a. burn-through. b. crater crack. c. porosity. d. Iack of fusion.

a. a misrun. b. a cold shut. c. rat tails. d. buckles.

c.1*s

*.1*d

210. A discontinuity in welds

215. An intermittent or continuous

dark line lbund at the edge ofthe weld groove or bevel would probabiy be

caused by gas entrapment in

the molten metal, moisture, improper cleaning, or lack ofpreheat is called:

classified as:

a. aligned porosity. b. slag line. c. root concavity.

a. dross. b. lack ofpenetration. c. porosity.

d'

slag

d'

inclusion'

216. A narrow, dark line

traveling in irregular directions would generally indicate the presence of:

A discontinuity consisting ofone or seteral parallel fissures caused by the internal rupture or fracture of material while in the hot semiplastic state is called:

D

cracking' &.-f7q

{.1*&

2ll.

crater

a. a crack. b. slag line. c. aligned porosity. d' lack of fusion'

a. lack offusion. b. tear. c. unfused chaplet. d. hot tear.

A.*s*

*. 1**

217.

Rodiogrophic Appeoronce of Disconlinuilies

A very thin, straight, dark line, either continuous or intermittent, located paraliel to and normally on one side of a weld would be indicative of:

212. A term

used to describe the oxides and other solids, which are shown radiographically as elongated or rounded inclusions, is:

a. slag. b. porosity. c. suck-up. d. wormhoies.

a. slag inclusion. b. suck-up. c. aligned porosity. d. lack of fusion. A :O?

218. f

.1t!$

The term used to describe a groove or depression located at the junction of the weld and base material on the weld surlace is:

213. An indication appearing

on a radiograph as a dark, elongated area ofvarying length or width located at the center of a weld would probably be classified as:

a. aligned porosity. b. slag line. c. wagon tracks. d. Iack ofpenetration.

a. convexity. b. undercut. c. lack offusion. d. concavity. A"3lC

*.

r86

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The Americon SocietY for Nondestructive Testing, lnc.

Cotolog Number: 2026 ISBN: 978-1 -57 1 17-335-5