ASTM E1496-05(2010)
(Test Method)Standard Test Method for Neutron Radiographic Dimensional Measurements (Withdrawn 2012)
Standard Test Method for Neutron Radiographic Dimensional Measurements (Withdrawn 2012)
SIGNIFICANCE AND USE
Many requirements exist for accurate dimensional information in industrial quality control. Frequently, this information cannot be measured directly, may be very uncertain, or is expensive to obtain. If a radiograph of the object in question displays a sufficient film density variation near the edge of interest, however, dimensional radiography methods may be applied. This test method provides a technique for extracting quantitative dimensional information from the neutron radiograph of an object. Guide E94 and Practices E748 are helpful for understanding the principles involved in obtaining a high-quality neutron radiograph.
Dimensional radiography appears to be particularly relevant in determination of the following: (1) diameters of spent radioactive fuel, (2) gap sizes in contact-circuit mechanisms of shielded components, and (3) prescribed spacings between distinct materials.
While this test method addresses dimensional measurements using neutron radiography, the methods and techniques of dimensional radiography are also equally applicable to various types of radiography, such as x-ray, γ-ray, and neutron.
A fundamental assumption of this test method is that the user will have access to a system that permits the attainment of data describing the density response of the radiograph. Although a system may include any digitization equipment capable of providing the spatial resolutions recommended in 6.1.1, a typical system will include a high-resolution traveling-stage microdensitometer and a neutron radiograph of the object.
An object with accurately known dimensions must be available to calibrate the equipment used to measure the radiographic response, that is, the traveling-stage microdensitometer (or other digitization system capable of spatial resolution comparable to that of the detector).
SCOPE
1.1 This test method provides a technique for extracting quantitative dimensional information on an object from its neutron radiograph. The technique is based on the identification of changes in film density caused by material changes where a corresponding discontinuity in film density exists. This test method is designed to be used with neutron radiographs made with a well-collimated beam. The film densities in the vicinity of the edge must be in the linear portion of the density versus exposure curve. The accuracy of this test method may be affected adversely in installations with high-angular-divergence neutron beams or with large object-to-film distances.
1.2 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.
WITHDRAWN RATIONALE
This test method provides a technique for extracting quantitative dimensional information on an object from its neutron radiograph. The technique is based on the identification of changes in film density caused by material changes where a corresponding discontinuity in film density exists. This test method is designed to be used with neutron radiographs made with a well-collimated beam. The film densities in the vicinity of the edge must be in the linear portion of the density versus exposure curve. The accuracy of this test method may be affected adversely in installations with high-angular-divergence neutron beams or with large object-to-film distances.
Formerly under the jurisdiction of Committee E07 on Nondestructive Testing, this test method was withdrawn in June 2012. This standard is being withdrawn without replacement due to its limited use by industry.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E1496 – 05 (Reapproved 2010)
Standard Test Method for
Neutron Radiographic Dimensional Measurements
This standard is issued under the fixed designation E1496; 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.
1. Scope Certification of Nondestructive Testing Personnel
NAS-410 Nondestructive Testing Personnel Qualification
1.1 This test method provides a technique for extracting
and Certification
quantitative dimensional information on an object from its
neutron radiograph. The technique is based on the identifica-
tion of changes in film density caused by material changes
whereacorrespondingdiscontinuityinfilmdensityexists.This
test method is designed to be used with neutron radiographs
made with a well-collimated beam. The film densities in the
vicinity of the edge must be in the linear portion of the density
versus exposure curve. The accuracy of this test method may
be affected adversely in installations with high-angular-
divergence neutron beams or with large object-to-film dis-
tances.
1.2 This standard does not purport to address all of the
FIG. 1 Typical Microdensitometer Film Density Traces Associated
safety concerns, if any, associated with its use. It is the
with Three Rectangular Material Discontinuities: (a) Edge of
responsibility of the user of this standard to establish appro-
Object, (b) Thickness Variation, and (c) Dissimilar Material
priate safety and health practices and determine the applica-
Boundary
bility of regulatory limitations prior to use.
2. Referenced Documents
3. Terminology
2.1 ASTM Standards:
3.1 Definitions—Definitions of the many terms relative to
E94 Guide for Radiographic Examination
radiography (for example, X, gamma, and neutron radiogra-
E543 Specification for Agencies Performing Nondestruc-
phy) can be found in Terminology E1316.
tive Testing
3.2 Definitions of Terms Specific to This Standard:
E748 Practices for Thermal Neutron Radiography of Mate-
3.2.1 extremum—the point on the linear response portion of
rials
the curve of smoothed density versus location at which the
E803 Test Method for Determining the L/D Ratio of Neu-
slope is a maximum.
tron Radiography Beams
3.2.2 extremum slope criterion—the criterion that specifies
E1316 Terminology for Nondestructive Examinations
the edge of a discontinuity or an object, located at the spatial
2.2 Other Documents:
position corresponding to the extremum as determined from
SNT-TC-1A Recommended Practice for Nondestructive
examination of a radiograph.
Testing Personnel Qualification and Certification
3.2.3 linear response—a radiographic response where the
ANSI/ASNT CP-189 ASNT Standard for Qualification and
filmdensityacrossanedgewithinanobjectiscontainedinthe
linear part of the density versus exposure curve.
3.2.4 traveling-stage microdensitometer—a densitometer
This test method is under the jurisdiction of ASTM Committee E07 on
withasmallaperture(typicallybetween10to25µmby200to
Nondestructive Testing and is the direct responsibility of Subcommittee E07.05 on
Radiology (Neutron) Method. 300 µm) that has the capability of scanning a radiograph in a
Current edition approved June 1, 2010. Published November 2010. Originally
continuousorsteppedmannerandgeneratingeitheradigitalor
approved in 1992. Last previous edition approved in 2005 as E1496-05. DOI:
an analog mapping of the film density of the radiograph as a
10.1520/E1496-05R10.
function of position.
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.
3 4
AvailablefromTheAmericanSocietyforNondestructiveTesting(ASNT),P.O. Available fromAerospace IndustriesAssociation ofAmerica, Inc. (AIA), 1250
Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518. Eye St., NW, Washington, DC 20005.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E1496 – 05 (2010)
FIG. 2 Typical Microdensitometer Traces of Film Density for (a)
Rectangular Objects and (b) Cylindrical Objects; Note
Placements of Edges x and x on the Traces
+ −
4. Summary of Test Method
4.1 All radiation used in radiography is attenuated in its
FIG. 3 Depiction of Various Slopes on a Smoothed
passage through an object according to its thickness and
Microdensitometer Trace; The Object Edge Coordinate, x ,
+
magnitude of the material attenuation properties appropriate to
Corresponds to the Extremum Slope Point on the Trace
the type and energy of radiation. Additionally, significant
spatial spreading occurs due to the system imperfections,
nonsymmetric radiation transport, and image formation pro-
for understanding the principles involved in obtaining a high-
cess.Significantvariationsintherecordedradiationnearedges
quality neutron radiograph.
and material discontinuities therefore occur and manifest
5.2 Dimensional radiography appears to be particularly
themselves by film density variations in the radiograph, as
relevant in determination of the following: (1) diameters of
illustrated in Fig. 1.
spent radioactive fuel, (2) gap sizes in contact-circuit mecha-
4.2 A graph of detector response (film density) versus
nisms of shielded components, and (3) prescribed spacings
location across an interface is similar in form for many
between distinct materials.
differenttypesofinterface,providedthatthedetectorresponds
5.3 While this test method addresses dimensional measure-
linearlytoincreasedexposureovertheentireregionofinterest.
ments using neutron radiography, the methods and techniques
TypicalradiographicresponsesareshowninFig.2(a)and(b).
of dimensional radiography are also equally applicable to
4.3 Both theoretical and experimental studies in neutron
varioustypesofradiography,suchasx-ray, g-ray,andneutron.
radiography have established that under commonly encoun-
5.4 Afundamentalassumptionofthistestmethodisthatthe
tered high-quality linear-response radiographic conditions, the
userwillhaveaccesstoasystemthatpermitstheattainmentof
edge of an object corresponds to that point on the smoothed
data describing the density response of the radiograph. Al-
experimentally obtained microdensitometer trace at which the
though a system may include any digitization equipment
slopeisamaximum,asillustratedinFig.3.Thispointiscalled
capable of providing the spatial resolutions recommended in
theextremum,andtherelationshipbetweenthespatialposition
6.1.1,atypicalsystemwillincludeahigh-resolutiontraveling-
of the extremum and location of the edge is called the
stage microdensitometer and a neutron radiograph of the
extremum slope criterion. These have been confirmed by
object.
careful experimentation (1-3).
5.5 An object with accurately known dimensions must be
available to calibrate the equipment used to measure the
5. Significance and Use
radiographic response, that is, the traveling-stage microdensi-
tometer (or other digitization system capable of spatial resolu-
5.1 Many requirements exist for accurate dimensional in-
tion comparable to that of the detector).
formation in industrial quality control. Frequently, this infor-
mation cannot be measured directly, may be very uncertain, or
6. Basis of Application
is expensive to obtain. If a radiograph of the object in question
displays a sufficient film density variation near the edge of 6.1 The following items are subject to contractual agree-
interest, however, dimensional radiography methods may be
ment between parties using or referencing this test method.
applied. This test method provides a technique for extracting 6.1.1 Personnel Qualification—If specified in the contrac-
quantitative dimensional information from the neutron radio-
tual agreement, personnel performing examinations in accor-
graph of an object. Guide E94 and Practices E748 are helpful dance with this test method shall be qualified in accordance
with a nationally or internationally recognized NDT personnel
qualificationpracticeorstandardsuchasANSI/ASNTCP-189,
SNT-TC-1A, NAS-410, or a similar document and certified by
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
this test method. the employer or certifying agency, as applicable. The practice
E1496 – 05 (2010)
orstandardusedanditsapplicablerevisionshallbespecifiedin 9.2 The dimensions of interest are deduced from the coor-
the contractual agreement between the using parties. dinates of either individual edges of the object or edges of
6.1.2 Qualification of Nondestructive Agencies—If speci- material discontinuities within the object. Hence, it is neces-
fied in the contractual agreement, NDT agencies shall be sary to describe only the methodology of determining the
qualified and evaluated as described in Practice E543. The
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