ASTM E1114-92(1997)e1

Standard Test Method for Determining the Focal Size of Iridium-192 Industrial Radiographic Sources

SCOPE
1.1 This test method covers the determination of the focal size of an iridium-192 radiographic source. The determination is based upon measurement of the image of the iridium metal source in a projection radiograph of the source assembly and comparison to the measurement of the image of a reference sample in the same radiograph.  
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.

General Information

• Status: Historical
• Publication Date: 09-Feb-1997
• ICS: 19.100 - Non-destructive testing
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.01 - Radiology (X and Gamma) Method

Relations

• Replaced By: ASTM E1114-03 - Standard Test Method for Determining the Focal Size of Iridium-192 Industrial Radiographic Sources
• Effective Date: 10-Mar-2003
• Referred By: ASTM E2033-17 - Standard Practice for Radiographic Examination Using Computed Radiography (Photostimulable Luminescence Method)
• Effective Date: 10-Feb-1997

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
An American National Standard
e1
Designation: E 1114 – 92 (Reapproved 1997)
Standard Test Method for
Determining the Focal Size of Iridium-192 Industrial
Radiographic Sources
This standard is issued under the fixed designation E 1114; 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.
e NOTE—Section 10 was added editorially in February 1997.
1. Scope object and object to film distances appropriate for maintaining
the desired degree of geometric unsharpness.
1.1 This test method covers the determination of the focal
size of an iridium-192 radiographic source. The determination
5. Apparatus
is based upon measurement of the image of the iridium metal
5.1 Subject Iridium-192 Source, the focal size of which is to
source in a projection radiograph of the source assembly and
be determined. The appropriate apparatus and equipment for
comparison to the measurement of the image of a reference
the safe storage, handling, and manipulation of the subject
sample in the same radiograph.
source, such as a radiographic exposure device (also referred to
1.2 This standard does not purport to address all of the
as a gamma ray projector or camera), remote control, source
safety concerns, if any, associated with its use. It is the
guide tube, and source stop are also required.
responsibility of the user of this standard to establish appro-
5.2 Reference Sample (see Figs. 1-3)—The reference
priate safety and health practices and determine the applica-
sample shall be of material which is not radioactive. The
bility of regulatory limitations prior to use.
recommended material is iridium. However, substitutes such as
2. Referenced Documents platinum, tungsten or other material of similar radiopacity may
be used. The sample should be of the same geometric shape as
2.1 ASTM Standards:
the subject source, should be approximately the same size as
E 999 Guide for Controlling the Quality of Industrial Ra-
the subject source, and should be positioned on or within a
diographic Film Processing
shim or envelope to simulate the source capsule wall. The
E 1316 Terminology for Nondestructive Testing
resulting radiographic contrast, with reference to adjacent
3. Terminology
background density of the image of the reference sample,
should be approximately the same as that of the subject source.
3.1 For definitions of terms relating to this test method, refer
The actual dimensions of the reference sample should be
to Terminology E 1316.
determined to the nearest 0.025 mm (0.001 in.).
4. Significance and Use
5.3 X-ray Generator, capable of producing a radiation
intensity (roentgen per hour at one metre) at least ten times
4.1 One of the factors affecting the quality of a radiographic
greater than that produced by the subject source. Examples of
image is geometric unsharpness. The degree of geometric
typical X-ray generator output requirements that satisfy this
unsharpness is dependent upon the focal size of the source, the
criterion are presented in Table 1.
distance between the source and the object to be radiographed,
5.4 Film, industrial type fine grain, extra fine grain, or ultra
and the distance between the object to be radiographed and the
fine grain as defined by the film manufacturer shall be used.
film. This test method allows the user to determine the focal
Selection of film type should be determined by such factors as
size of the source and to use this result to establish source to
the required radiographic quality level, equipment capability,
materials, and so forth. The films selected must be capable of
This test method is under the jurisdictioin of ASTM Committee E-7 on
demonstrating the required image quality. No intensifying
Nondestructive Testing and is the direct responsibility of Subcommittee E07.01 on
screens should be used. The film should be processed in
Radiographic Practice and Penetrameters.
accordance with Guide E 999.
Current edition approved Sept. 15, 1992. Published November 1992. Originally
published as E1114 – 86. Last previous edition E1114 – 86.
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.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
e1
E 1114 – 92 (1997)
FIG. 1 Reference Sample in Standard Source Encapsulation
FIG. 2 Alternate Reference Sample Arrangement
FIG. 3 Alternate Reference Sample Arrangement
TABLE 1 Examples of Typical X-ray Generator Output
5.5 Image Measurement Apparatus—This apparatus is used 192
Requirements for Related Iridium Source Activities
to measure the size of the image of the focal spot. The
Subject Iridium Source Typical X-ray Generator
apparatus shall be an optical comparator with built-in graticule
Radiation Output Requirements
with 0.1 mm divisions or 0.001 in. divisions and magnification
Activity Output
Potential Current
of 53 to 103. (Curie) (R/h at 1 m)
6. Procedure
30 14.4 160 kV 5 mA
or 200 kV 3 mA
6.1 Set up the exposure arrangement as shown in Figs. 4-7.
100 48.0 160 kV 10 mA
Position the X-ray tube directly over the center of the film. The or 250 kV 4 mA
200 96.0 160 kV 20 mA
film plane must be normal to the central ray of the X-ray beam.
or 250 kV 8 mA
The X-ray focal spot should be 0.90 m (36 in.) from the film.
or 300 kV 6 mA
Position the reference sample and apparatus used to locate the
subject source (source stop) as close together as possible and
directly over the center of the film. The plane of the source stop
and reference sample must be parallel to the film and normal to device by the shortest source guide tube practicable in order to
the central ray of the X-ray beam. The source stop and minimize fogging of the film during source transit.
reference sample should be 0.15 m (6 in.) from the film. The 6.2 Place identification markers to be imaged on the film to
source stop should be connected to the radiographic exposure identify, as a minimum, the identification (serial number) of the
NOTICE: This standard has either been superceded an
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