ASTM E1815-08(2013)e1
(Test Method)Standard Test Method for Classification of Film Systems for Industrial Radiography
Standard Test Method for Classification of Film Systems for Industrial Radiography
SIGNIFICANCE AND USE
4.1 This test method provides a relative means for classification of film systems used for industrial radiography. The film system consists of the film and associated processing system (the type of processing and processing chemistry). Section 9 describes specific parameters used for this test method. In general, the classification for hard X-rays, as described in Section 9, can be transferred to other radiation energies and metallic screen types, as well as screens without films. The usage of film system parameters outside the energy ranges specified may result in changes to a film/system performance classification.
4.1.1 The film performance is described by contrast and noise parameters. The contrast is represented by gradient and the noise by granularity.
4.1.2 A film system is assigned a particular class if it meets the minimum performance parameters: for Gradient G at D – D0 = 2.0 and D – D0 = 4.0, and gradient/noise ratio at D – D0 = 2.0, and the maximum performance parameter: granularity σD at D = 2.0.
4.2 This test method describes how the parameters shall be measured and demonstrates how a classification table can be constructed.
4.3 Manufacturers of industrial radiographic film systems and developer chemistry will be the users of this test method. The result is a classification table as shown by the example given in Table 2. Another table also includes speed data for user information. Users of industrial radiographic film systems may also perform the tests and measurements outlined in this test method, provided that the required test equipment is used and the methodology is followed strictly.A Family of films ranging in speed and image quality.
4.4 The publication of classes for industrial radiography film systems will enable specifying bodies and contracting parties to agree to particular system classes, which are capable of providing known image qualities. See 8.
4.5 ISO 11699–1 and European standard EN 584-1 describe the same method ...
SCOPE
1.1 This test method covers a procedure for determination of the performance of film systems used for industrial radiography. This test method establishes minimum requirements that correspond to system classes.
1.2 This test method is to be used only for direct exposure-type film exposed with lead intensifying screens. The performance of films exposed with fluorescent (light-emitting) intensifying screens cannot be determined accurately by this test method.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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´1
Designation:E1815 −08 (Reapproved 2013)
Standard Test Method for
Classification of Film Systems for Industrial Radiography
This standard is issued under the fixed designation E1815; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Research Report number and ISO Standards updated editorially in June 2013
1. Scope gradients G2 and G4 When Exposed to X and Gamma
Radiation
1.1 This test method covers a procedure for determination
ISO 11699-1Non-Destructive Testing—Industrial Radio-
of the performance of film systems used for industrial radiog-
graphic Film—Part 1: Classification of Film Systems for
raphy.Thistestmethodestablishesminimumrequirementsthat
Industrial Radiography
correspond to system classes.
ISO 11699-2Non-Destructive Testing—Industrial Radio-
1.2 This test method is to be used only for direct exposure-
graphic Film—Part 2: Control of Film Processing by
type film exposed with lead intensifying screens. The perfor-
Means of Reference Values
manceoffilmsexposedwithfluorescent(light-emitting)inten-
ISO/IEC 17025General Requirements for the Competence
sifying screens cannot be determined accurately by this test
of Testing and Calibration Laboratories
method.
2.3 European CEN Standard:
1.3 The values stated in SI units are to be regarded as
EN 584-1 Non-Destructive Testing—Industrial Radio-
standard. The values given in parentheses are for information
graphic Film—Part 1: Classification of Film Systems for
only.
Industrial Radiography
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions—For definitions of terms used in this test
priate safety and health practices and determine the applica-
method, refer to Terminology E1316.
bility of regulatory limitations prior to use.
3.2 Definitions of Terms Specific to This Standard:
2. Referenced Documents
3.2.1 characteristic curve—curve showing the relationship
2.1 ASTM Standards: between the common logarithm of exposure logK, and the
E94Guide for Radiographic Examination optical density D.
E1316Terminology for Nondestructive Examinations
3.2.2 diffuse density—quantitative measure of film blacken-
2.2 ISO Standards:
ing (optical density) as determined by a densitometer. It is the
ISO 5-2Photography Density Measurements—Part 2: Geo-
sum of all transmitted and scattered light into the half sphere
metric Conditions for Transmission Density
behind the film.
ISO 5-3Photography and Graphic Technology—Density
3.2.3 film gradient G—the slope of the characteristic curve
Measurements—Part 3: Spectral Conditions
at a specified optical density, D, and a measure of the contrast
ISO7004Photography—IndustrialRadiographicFilms,De-
of the film system.
termination of ISO Speed, ISO average gradient and ISO
3.2.4 film system—the film and associated film-processing
requirements in accordance with the criteria established by the
This test method is under the jurisdiction of ASTM Committee E07 on
Nondestructive Testing and is the direct responsibility of Subcommittee E07.01 on manufacturers of the film and processing chemicals.
Radiology (X and Gamma) Method.
3.2.5 filmsystemclass—classificationtakingintoaccountof
Current edition approved June 1, 2013. Published June 2013. Originally
approved in 1996. Last previous edition approved in 2008 as E1815-08. DOI:
limiting values given in Table 1.
10.1520/E1815-08R13E01.
3.2.6 gradient/noise ratio—ratio of the gradient G and the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
granularity σ . It relates directly to the signal/noise ratio. All
D
Standards volume information, refer to the standard’s Document Summary page on
further parameters determining the signal, such as the modu-
the ASTM website.
lation transfer function or the energy of the radiation, are
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. considered to be constant.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E1815−08 (2013)
TABLE 1 Limiting Values for Gradient, Gradient/Granularity Ratio, and Granularity
Minimum Gradient G at Minimum Maximum
Gradient/ Granularity,
ASTM
Granularity σ ,at D=2.0
D
System
Ratio, G/σ , above D
D o
D=2.0 D=4.0
Class
at D=2.0
above D above D
o o
above D
o
Special 4.5 7.5 300 0.018
I 4.1 6.8 150 0.028
II 3.8 6.4 120 0.032
III 3.5 5.0 100 0.039
W-A 3.8 5.7 135 0.027
W-B 3.5 5.0 110 0.032
W-C <3.5 <5.0 80 0.039
The classification is only valid for the complete film system. In general, the classification for X-rays as described in 7.1 can be transferred to other
radiation energies and metallic screen types as well as films without screens and single coated films.
A certificate shall contain the following information:
–reference to this standard
–date
–measured values of gradient at D = 2 and D = 4 above fog and base
–measured granularity at D = 2 above fog and base
–calculated value of (D/σ )at D = 2 above fog and base
D
–Dose K for D = 2 above fog and base
S
–Processing conditions:
–Manual or automatic
–Type of chemistry
–Developer immersion time
–Developer temperature
–Classification in accordance with Table 1
Table 2 gives an example for a classification result of different film types, a developer system and given developing conditions.
3.2.6.1 Discussion—The limiting values given in this stan- 4.1.1 The film performance is described by contrast and
dard are related to fixed radiation energies and specified noise parameters. The contrast is represented by gradient and
screens.
the noise by granularity.
3.2.7 granularity, σ —stochastic fluctuation in a radio- 4.1.2 Afilm system is assigned a particular class if it meets
D
graphic image, superimposed on the image of the object and
the minimum performance parameters: for Gradient G at
typically caused by random, statistical groupings of individual D–D =2.0 and D–D =4.0, and gradient/noise ratio at
0 0
silver particles in processed film.
D – D = 2.0, and the maximum performance parameter:
granularity σ at D=2.0.
3.2.8 ISO speed S—reciprocal value of the dose K mea- D
S
sured in Gray, which results in a specified diffuse optical
4.2 This test method describes how the parameters shall be
transmission density D– D =2 on the processed film, where
measured and demonstrates how a classification table can be
D is the fog and base density:
constructed.
S 5 (1)
4.3 Manufacturers of industrial radiographic film systems
K
S
and developer chemistry will be the users of this test method.
3.2.9 signal/noise ratio—in industrial radiography the ratio
The result is a classification table as shown by the example
ofalocalfilmdensitytothegranularityσ atthisdensitylevel.
D
given in Table 2. Another table also includes speed data for
It is correlated to the gradient/noise ratio.
user information. Users of industrial radiographic film systems
3.2.10 specular density—quantitative measure of film
may also perform the tests and measurements outlined in this
blackening (optical density) when light passing the optics of a
test method, provided that the required test equipment is used
microdensitometer transmits the film.
and the methodology is followed strictly.
4. Significance and Use
4.4 The publication of classes for industrial radiography
film systems will enable specifying bodies and contracting
4.1 This test method provides a relative means for classifi-
parties to agree to particular system classes, which are capable
cationoffilmsystemsusedforindustrialradiography.Thefilm
of providing known image qualities. See 8.
system consists of the film and associated processing system
(the type of processing and processing chemistry). Section 9
4.5 ISO11699–1andEuropeanstandardEN584-1describe
describes specific parameters used for this test method. In
thesamemethodforclassificationoffilmsystemsforindustrial
general, the classification for hard X-rays, as described in
radiography, but its class definitions and number of classes do
Section 9, can be transferred to other radiation energies and
not align exactly with this test method. International users of
metallic screen types, as well as screens without films. The
these standards should be aware of these differences for their
usage of film system parameters outside the energy ranges
particular applications.
specified may result in changes to a film/system performance
classification. NOTE 1—ASTM research report E07–1005 contains documentation of
´1
E1815−08 (2013)
TABLE 2 Typical Film System Classification
Automatic Film Processing
Developer: Type A
Developer immersion time: XXX seconds
Developer temperature: XX°C/YY°F
Minimum
Minimum Gradient G at
Gradient/ Maximum
ASTM System Granularity Granularity, σ , ISO Speed Dose, K,m Gy,
A D s
Film Type
Class Ratio, G/σ ,at at D = 2.0 above S D=2.0
D
D=2.0 D=4.0
D = 2.0 above D
o
above D above D
o o
D
o
A Special 5.4 9.1 360 0.015 32 29.0
B I 4.5 8.4 281 0.016 64 14.0
C I 4.4 7.6 232 0.019 100 8.7
D I 4.4 7.6 169 0.026 200 4.6
E II 4.4 7.6 142 0.031 320 3.2
F III 4.0 5.2 114 0.035 400 2.5
G W-A 4.2 6.5 225 0.019 100 8.6
H W-B 4.1 5.3 170 0.025 200 5.0
A
Family of films ranging in speed and image quality.
technical methods used during the development of this test method.
inselectingandstoringsamplesasdescribedaboveistoensure
the film characteristics are representative of those obtained by
5. Microdensitometer Requirements
a consumer at the time of use.
5.1 The influx aperture of the microdensitometer shall be
approximately circular in shape, with a diameter (referred to
7. Test Method
the plane of the specimen) not less than 1.2× or more than 2×
7.1 Preparation
the diameter of the efflux aperture.
7.1.1 The film samples shall be exposed to X-rays from
5.2 The reduction of the influx aperture by the influx optics
tungsten target tubes. Inherent filtration of the tube, plus an
and the magnification of the specimen onto the efflux aperture
additionalcopperfilterlocatedasclosetotheX-raytubetarget
by the efflux optics shall lie in the range from 20 to 100×. The
as possible shall provide filtration equivalent to (8.00 6 0.05)
two magnifications need not be equal.
mm of copper. The potential across the X-ray tube shall be
5.3 The efflux (or measuring aperture) shall be preferably
adjusteduntilthehalf-value-absorptionisobtainedwith(3.5 6
circular in shape. Its effective diameter referred to the speci-
0.2) mm of copper. A potential of approximately 220 kV
men plane shall be 100 6 5 µm.
generally meets this requirement.
5.4 The spectral response of the microdensitometer system
7.1.2 Thefilmsystemshallincludeafrontandabackscreen
shall be visual, as specified by ISO 5-3.
of 0.02 to 0.04 mm lead. If single coated films are used, the
5.5 An electronic band-pass filter, used to reduce the un-
emulsion coated surface shall face the X-ray tube. Good film
wanted signal caused by system artifacts, shall have its
screen contact shall be ensured.
low-frequency boundary set so the system response is 3 dB
7.1.3 Exercisecaretoensurethatthefilmspecimendoesnot
down at a temporal frequency corresponding to a spatial
containdensityvariationsarisingfromtheexposingequipment
frequencyof0.1cycles/mm.Itshigh-frequencyboundaryshall
(such as non-uniform beam filters or damaged, or defective
be set so that the system response is 3 dB down at a temporal
lead screens) or processing system. During and after exposure,
frequency corresponding to the first zero in the spatial fre-
priortoprocessing,maintainthefilmspecimenatthetempera-
quency response of the circular aperture. Mathematical proce-
ture of 23°C 6 5°C and relative humidity of 50 6 20%. The
duresthatcanbeshowntoproduceequivalentreductionsinthe
filmprocessingchemicalsandproceduresshallbethesamefor
effects of system artifacts are acceptable alternatives to the use
determining gradient and granularity, and they shall be used
of this filter (see 7.3).
and described completely as specified.
6. Sampling and Storage
7.1.4 Use manufacturer certified film test strips in accor-
dance with ISO 11699-2 to test the specified developer system
6.1 Forproductspecificationitisimportantthatthesamples
with the specified immersion time and developer temperature.
evaluated yield the average results obtained by users.This will
require the evaluation of several different batches periodically ThespeedindexS shallbewithin 65%ofthemanufacturer’s
x
under conditions specified in this standard. Prior to evaluation, certificate. The developer temperature may differ by 61°C
the samples shall be stored according to the manufacturers’
from the certified value to adjust S within 65% of the
X
recommendations for a length of time to simulate the average
manufacturer certificate value. The obtained S and used
X
age at which the product is normally used.The basic objective
developer temperature shall be documented in the test report.
This test shall be done, on a daily basis, before and after the
4 development of the exposed films for classification with the
Supporting data have been filed atASTM International Headquarters and may
be obtained by requesting Research Report RR:E07-1005. same developer temperature and immersion time.
´1
E1815−08 (2013)
7.1.5 If a manufacturer certificate is not available, film test film, exposure, and processing techniques as used for the
strips shall be manufactured and calibrated according to ISO granularity film specimen.The specimen film shall be scanned
11699-2 by the user. using identical microdensitometer settings. A limited range of
densities can typically be measured for a given microdensi-
7.2 Measurement of Gradient G:
tometer gain setting.
7.2.1 Gradient G relates to a D versus log K curve. In the
7.3.5 The stepped series of densities shall lie within that
dD
scope of this test method, G is calculated from the slope ⁄dK
range.
of a D versus K curve at density (D−D ), as follows:
o
7.3.6 The calibration shall be made from the diffuse vs
dD K dD
specular density plot with at least five values between diffuse
G 5 5 3 (2)
d log K log e dK
10 10 density 1.5 and 2.8 (including fog and base). The conversion
canbeperformedonbasisofalinearregressionanalysisofthe
where:
log (diffuse density) vs. log (specular density) plot. The
K = dose required for density D−D , and
o
determined coefficients shall be used fo
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: E1815 − 08 E1815 − 08 (Reapproved 2013)
Standard Test Method for
Classification of Film Systems for Industrial Radiography
This standard is issued under the fixed designation E1815; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Research Report number and ISO Standards updated editorially in June 2013
1. Scope
1.1 This test method covers a procedure for determination of the performance of film systems used for industrial radiography.
This test method establishes minimum requirements that correspond to system classes.
1.2 This test method is to be used only for direct exposure-type film exposed with lead intensifying screens. The performance
of films exposed with fluorescent (light-emitting) intensifying screens cannot be determined accurately by this test method.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E94 Guide for Radiographic Examination
E1316 Terminology for Nondestructive Examinations
2.2 ISO Standards:
ISO 5-2 Photography Density Measurements—Part 2: Geometric Conditions for Transmission Density
ISO 5-3 Photography Density and Graphic Technology—Density Measurements—Part 3: Spectral Conditions
ISO 7004 Photography—Industrial Radiographic Film,Films, Determination of ISO Speed and Average Gradient Speed, ISO
average gradient and ISO gradients G2 and G4 When Exposed to X and Gamma Radiation
ISO 11699-1 Non-Destructive Testing—Industrial Radiographic Film—Part 1: Classification of Film Systems for Industrial
Radiography
ISO 11699-2 Non-Destructive Testing—Industrial Radiographic Film—Part 2: Control of Film Processing by Means of
Reference Values
ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories
2.3 European CEN Standard:
EN 584-1 Non-Destructive Testing—Industrial Radiographic Film—Part 1: Classification of Film Systems for Industrial
Radiography
3. Terminology
3.1 Definitions—For definitions of terms used in this test method, refer to Terminology E1316.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 characteristic curve—curve showing the relationship between the common logarithm of exposure logK, and the optical
density D.
This test method is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.01 on Radiology
(X and Gamma) Method.
Current edition approved July 1, 2008June 1, 2013. Published August 2008June 2013. Originally approved in 1996. Last previous edition approved in 20062008 as
E1815 - 06.E1815 - 08. DOI: 10.1520/E1815-08.10.1520/E1815-08R13E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E1815 − 08 (2013)
3.2.2 diffuse density—quantitative measure of film blackening (optical density) as determined by a densitometer. It is the sum
of all transmitted and scattered light into the half sphere behind the film.
3.2.3 film gradient G—the slope of the characteristic curve at a specified optical density, D, and a measure of the contrast of
the film system.
3.2.4 film system—the film and associated film-processing requirements in accordance with the criteria established by the
manufacturers of the film and processing chemicals.
3.2.5 film system class—classification taking into account of limiting values given in Table 1.
3.2.6 gradient/noise ratio—ratio of the gradient G and the granularity σ . It relates directly to the signal/noise ratio. All further
D
parameters determining the signal, such as the modulation transfer function or the energy of the radiation, are considered to be
constant.
3.2.6.1 Discussion—
The limiting values given in this standard are related to fixed radiation energies and specified screens.
3.2.7 granularity, σ —stochastic fluctuation in a radiographic image, superimposed on the image of the object and typically
D
caused by random, statistical groupings of individual silver particles in processed film.
3.2.8 ISO speed S—reciprocal value of the dose K measured in Gray, which results in a specified diffuse optical transmission
S
density D – D = 2 on the processed film, where D is the fog and base density:
0 0
S 5 (1)
K
S
3.2.9 signal/noise ratio—in industrial radiography the ratio of a local film density to the granularity σ at this density level. It
D
is correlated to the gradient/noise ratio.
3.2.10 specular density—quantitative measure of film blackening (optical density) when light passing the optics of a
microdensitometer transmits the film.
4. Significance and Use
4.1 This test method provides a relative means for classification of film systems used for industrial radiography. The film system
consists of the film and associated processing system (the type of processing and processing chemistry). Section 9 describes
specific parameters used for this test method. In general, the classification for hard X-rays, as described in Section 9, can be
TABLE 1 Limiting Values for Gradient, Gradient/Granularity Ratio, and Granularity
Minimum Gradient G at Minimum Maximum
Gradient/ Granularity,
ASTM
Granularity σ , at D = 2.0
D
System
Ratio, G/σ , above D
D o
D = 2.0 D = 4.0
Class
at D = 2.0
above D above D
o o
above D
o
Special 4.5 7.5 300 0.018
I 4.1 6.8 150 0.028
II 3.8 6.4 120 0.032
III 3.5 5.0 100 0.039
W-A 3.8 5.7 135 0.027
W-B 3.5 5.0 110 0.032
W-C <3.5 <5.0 80 0.039
The classification is only valid for the complete film system. In general, the classification for X-rays as described in 7.1 can be transferred to other
radiation energies and metallic screen types as well as films without screens and single coated films.
A certificate shall contain the following information:
–reference to this standard
–date
–measured values of gradient at D = 2 and D = 4 above fog and base
–measured granularity at D = 2 above fog and base
–calculated value of (D/σ ) at D = 2 above fog and base
D
–Dose K for D = 2 above fog and base
S
–Processing conditions:
–Manual or automatic
–Type of chemistry
–Developer immersion time
–Developer temperature
–Classification in accordance with Table 1
Table 2 gives an example for a classification result of different film types, a developer system and given developing conditions.
´1
E1815 − 08 (2013)
transferred to other radiation energies and metallic screen types, as well as screens without films. The usage of film system
parameters outside the energy ranges specified may result in changes to a film/system performance classification.
4.1.1 The film performance is described by contrast and noise parameters. The contrast is represented by gradient and the noise
by granularity.
4.1.2 A film system is assigned a particular class if it meets the minimum performance parameters: for Gradient G at
D – D = 2.0 and D – D = 4.0, and gradient/noise ratio at D – D = 2.0, and the maximum performance parameter: granularity σ
0 0 0 D
at D = 2.0.
4.2 This test method describes how the parameters shall be measured and demonstrates how a classification table can be
constructed.
4.3 Manufacturers of industrial radiographic film systems and developer chemistry will be the users of this test method. The
result is a classification table as shown by the example given in Table 2. Another table also includes speed data for user information.
Users of industrial radiographic film systems may also perform the tests and measurements outlined in this test method, provided
that the required test equipment is used and the methodology is followed strictly.
4.4 The publication of classes for industrial radiography film systems will enable specifying bodies and contracting parties to
agree to particular system classes, which are capable of providing known image qualities. See 8.
4.5 ISO 11699–1 and European standard EN 584-1 describe the same method for classification of film systems for industrial
radiography, but its class definitions and number of classes do not align exactly with this test method. International users of these
standards should be aware of these differences for their particular applications.
NOTE 1—ASTM research report E07–1005 contains documentation of technical methods used during the development of this test method.
5. Microdensitometer Requirements
5.1 The influx aperture of the microdensitometer shall be approximately circular in shape, with a diameter (referred to the plane
of the specimen) not less than 1.2× or more than 2× the diameter of the efflux aperture.
5.2 The reduction of the influx aperture by the influx optics and the magnification of the specimen onto the efflux aperture by
the efflux optics shall lie in the range from 20 to 100×. The two magnifications need not be equal.
5.3 The efflux (or measuring aperture) shall be preferably circular in shape. Its effective diameter referred to the specimen plane
shall be 100 6 5 μm.
5.4 The spectral response of the microdensitometer system shall be visual, as specified by ISO 5-3.
5.5 An electronic band-pass filter, used to reduce the unwanted signal caused by system artifacts, shall have its low-frequency
boundary set so the system response is 3 dB down at a temporal frequency corresponding to a spatial frequency of 0.1 cycles/mm.
Its high-frequency boundary shall be set so that the system response is 3 dB down at a temporal frequency corresponding to the
first zero in the spatial frequency response of the circular aperture. Mathematical procedures that can be shown to produce
equivalent reductions in the effects of system artifacts are acceptable alternatives to the use of this filter (see 7.3).
Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:E07-1005.
TABLE 2 Typical Film System Classification
Automatic Film Processing
Developer: Type A
Developer immersion time: XXX seconds
Developer temperature: XX°C/YY°F
Minimum
Minimum Gradient G at
Gradient/ Maximum
ASTM System Granularity Granularity, σ , ISO Speed Dose, K , m Gy,
A D s
Film Type
Class Ratio, G/σ , at at D = 2.0 above S D = 2.0
D
D = 2.0 D = 4.0
D = 2.0 above D
o
above D above D
o o
D
o
A Special 5.4 9.1 360 0.015 32 29.0
B I 4.5 8.4 281 0.016 64 14.0
C I 4.4 7.6 232 0.019 100 8.7
D I 4.4 7.6 169 0.026 200 4.6
E II 4.4 7.6 142 0.031 320 3.2
F III 4.0 5.2 114 0.035 400 2.5
G W-A 4.2 6.5 225 0.019 100 8.6
H W-B 4.1 5.3 170 0.025 200 5.0
A
Family of films ranging in speed and image quality.
´1
E1815 − 08 (2013)
6. Sampling and Storage
6.1 For product specification it is important that the samples evaluated yield the average results obtained by users. This will
require the evaluation of several different batches periodically under conditions specified in this standard. Prior to evaluation, the
samples shall be stored according to the manufacturers’ recommendations for a length of time to simulate the average age at which
the product is normally used. The basic objective in selecting and storing samples as described above is to ensure the film
characteristics are representative of those obtained by a consumer at the time of use.
7. Test Method
7.1 Preparation
7.1.1 The film samples shall be exposed to X-rays from tungsten target tubes. Inherent filtration of the tube, plus an additional
copper filter located as close to the X-ray tube target as possible shall provide filtration equivalent to (8.00 6 0.05) mm of copper.
The potential across the X-ray tube shall be adjusted until the half-value-absorption is obtained with (3.5 6 0.2) mm of copper.
A potential of approximately 220 kV generally meets this requirement.
7.1.2 The film system shall include a front and a back screen of 0.02 to 0.04 mm lead. If single coated films are used, the
emulsion coated surface shall face the X-ray tube. Good film screen contact shall be ensured.
7.1.3 Exercise care to ensure that the film specimen does not contain density variations arising from the exposing equipment
(such as non-uniform beam filters or damaged, or defective lead screens) or processing system. During and after exposure, prior
to processing, maintain the film specimen at the temperature of 23°C 6 5°C and relative humidity of 50 6 20 %. The film
processing chemicals and procedures shall be the same for determining gradient and granularity, and they shall be used and
described completely as specified.
7.1.4 Use manufacturer certified film test strips in accordance with ISO 11699-2 to test the specified developer system with the
specified immersion time and developer temperature. The speed index S shall be within 65 % of the manufacturer’s certificate.
x
The developer temperature may differ by 61°C from the certified value to adjust S within 65 % of the manufacturer certificate
X
value. The obtained S and used developer temperature shall be documented in the test report. This test shall be done, on a daily
X
basis, before and after the development of the exposed films for classification with the same developer temperature and immersion
time.
7.1.5 If a manufacturer certificate is not available, film test strips shall be manufactured and calibrated according to ISO 11699-2
by the user.
7.2 Measurement of Gradient G:
d D
7.2.1 Gradient G relates to a D versus log K curve. In the scope of this test method, G is calculated from the slope ⁄dK of
a D versus K curve at density (D − D ), as follows:
o
dD K dD
G 5 5 3 (2)
d log K log e dK
10 10
where:
K = dose required for density D − D , and
o
D = fog and base density.
o
7.2.2 The D versus K curve is approximated by a polynomial of thi
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