ASTM E242-01

Standard Reference Radiographs for Appearances of Radiographic Images as Certain Parameters Are Changed

SCOPE
1.1 This document describes the appearance of a radiographic image where fundamental components of image quality are changed, that is, variables such as whether a X-ray or gamma ray source was used, the characteristics of the radiographic film and intensifying screens, and the geometrical configuration of the object under investigation as well as its associated radiographic set-up.
1.2 These reference radiographs  consist of four composite illustrations  and show how such factors as radiation energy, specimen thickness, and film properties affect the radiographic image.  
1.3 The values stated in inch-pound units are to be regarded as the standard.
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.

General Information

• Status: Historical
• Publication Date: 09-Jun-2001
• ICS: 19.100 - Non-destructive testing
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.02 - Reference Radiological Images

Relations

• Replaces: ASTM E242-95(2000) - Standard Reference Radiographs for Appearances of Radiographic Images as Certain Parameters Are Changed
• Effective Date: 10-Jun-2001
• Replaced By: ASTM E242-01(2005)e1 - Standard Reference Radiographs for Appearances of Radiographic Images as Certain Parameters Are Changed
• Effective Date: 01-Dec-2005
• Referred By: ASTM E1032-19 - Standard Practice for Radiographic Examination of Weldments Using Industrial X-Ray Film
• Effective Date: 10-Jun-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E242–01
Standard Reference Radiographs for
Appearances of Radiographic Images as Certain Parameters
1
Are Changed
This standard is issued under the fixed designation E 242; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This document describes the appearance of a radio- 3.1 Definitions: For definitions of terms used in this docu-
graphic image where fundamental components of image qual- ment, see Terminology E 1316, Section D.
ity are changed, that is, variables such as whether an X-ray or
4. Significance and Use
gamma ray source was used, the characteristics of the radio-
graphic film and intensifying screens, and the geometrical 4.1 A key consideration with any radiographic system is its
capability to resolve detail (that is, sensitivity). The degree of
configuration of the object under investigation as well as its
associated radiographic set-up. obtainable sensitivity with a given system is dependent upon
2
several radiographic parameters such as source energy level,
1.2 These reference radiographs consist of four composite
3
illustrations and show how such factors as radiation energy, film system, type and thickness of intensifying screens, and
material thickness radiographed. These reference radiographs
specimen thickness, and film properties affect the radiographic
image. permit the user to estimate the degree of sensitivity change that
may be obtained when these parameters are varied from a
1.3 The values stated in inch-pound units are to be regarded
as the standard. specific technique. This standard may also be used in conjunc-
tion with Test Method E 1815 or with Test Method E 746 to
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the provide a basis for developing data for evaluation of a user’s
specific system. This data may assist a user in determining
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- appropriate parameters for obtaining desired degrees of radio-
graphic system sensitivity.
bility of regulatory limitations prior to use.
5. Factors Affecting Radiographic Appearance
2. Referenced Documents
2.1 ASTM Standards: 5.1 The final interpretation of the radiograph is greatly
4
affected by the appearance of a discontinuity.Apoor technique
E 94 Guide for Radiographic Examination
E 746 Test Method for Determining Relative Image Quality can minimize the radiographic appearance of a discontinuity
4
and conversely the optimum technique can emphasize this
Response of Industrial Radiographic Film
4
E 1316 Terminology for Nondestructive Examinations appearance.Theappearanceofaradiographicimageisaffected
mainly by:
E 1815 Test Method for Classification of Film Systems for
4
Industrial Radiography 5.1.1 X-ray or gamma ray energy.
5.1.2 Section thickness,
2.2 ASTM Adjuncts:
Reference Radiographs for Appearances of Radiographic 5.1.3 Unsharpness, and
3
5.1.4 Film and screen combinations.
Images as Certain Parameters Are Changed
5.2 The equation that considers most of the above factors is:
Dx 5 @c~d 2 d !/Gµ#~kx 1 1! (1)
1 1 2
These reference radiographs are under the jurisdiction of ASTM Committee
E07 on Nondestructive Testing and are the direct responsibility of Subcommittee
where:
E07.02 on Reference Radiographs.
Dx = thickness of discontinuity,
Current edition approved June 10, 2001. Published August 2001. Originally
c = constant,
published as E 242 – 64 T. Last previous edition E 242 – 95 (2000).
2
For ASME Boiler and Pressure Code applications see related Reference
d −d = minimum density change perceptible by eye,
1 2
Radiographs SE-242 in the Code.
G = film gradient,
3
Available from ASTM Headquarters. Order RRE0242.
µ = linear absorption coefficient (effective),
4
Annual Book of ASTM Standards, Vol 03.03.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E242–01
7. Use of the Reference Radiographs
k = scattering coefficient, and
x = section thickness.
7.1 As radiation energy increases, the radiographic appear-
As the above equation shows, the minimum thickness of
ance of a given discontinuity becomes less distinct because of
detectable discontinuity (Dx) is:
the greater penetration of the radiation; that is, because of
5.2.1 A function of X-ray energy,
decreasing subject contrast.The reference radiographs permit a
5.2.2 A function of section thickness, and
comparison of the radiographic appearan
...