Association News

ASTM Standard aids in measurement of X-ray focal point size.

Press Release Summary:

Nov 18, 2014 - ASTM E2903, Test Method for Measurement of the Effective Focal Spot Size of Mini and Micro Focus X-Ray Tubes will be useful for X-ray tube manufacturers as well as practitioners of digital radiography. Results generated from use of standard can be used to establish source-to-object and object-to-image detector distances appropriate for maintaining desired degree of geometric unsharpness or maximum magnification possible, or both, for given radiographic imaging application.

ASTM International - West Conshohocken, PA

Original Press Release

ASTM International Standard Aids in Measurement of X-Ray Focal Point Size

Press release date: Oct 20, 2014

The quality and resolution of X-ray images depends on the characteristics of the focal point, the area that is struck by electrons and from which the resulting X-rays are emitted. A new ASTM International standard will allow users to determine the effective focal spot size of an X-ray source.

The new standard is ASTM E2903, Test Method for Measurement of the Effective Focal Spot Size of Mini and Micro Focus X-Ray Tubes. X-Ray tube manufacturers will find the standard helpful when supplying customers with focal spot size, or for quality control.

Additionally, “knowledge of focal spot size is very important to practitioners of digital radiography because magnification principles need to be applied to compensate for the limited spatial resolution of digital X-ray image detectors,” says ASTM member David Fry, research and development engineer, Los Alamos National Laboratory.

Fry explains that, in radiography, the blurring of image edges is a function of the geometry of the setup and the focal spot size.

“Digital images are also blurred by the pixel size and X-ray to light conversion screens,” Fry says. “Digital images are thus blurred by combination of focal spot size, geometry and digital detector characteristics.”

Results generated from the use of ASTM E2903 can be used to establish source-to-object and object-to-image detector distances appropriate for maintaining the desired degree of geometric unsharpness or maximum magnification possible, or both, for a given radiographic imaging application. ASTM standard practices E2698 and E2033 for radiographic examination using digital methods require knowledge of focal spot size.

ASTM E2903 was developed by Subcommittee E07.01 on Radiology (X and Gamma) Method, part of ASTM Committee E07 on Nondestructive Testing. E07.01 encourages all interested parties to participate in its standards developing activities. The subcommittee is particularly interested in feedback on how ASTM E2903 is being applied, as well as additional data for refinement of the standard’s precision and bias statement.

To purchase standards, visit www.astm.org and search by the standard designation, or contact ASTM Customer Relations (tel +1.877.909.ASTM; sales@astm.org). ASTM welcomes participation in the development of its standards. Become a member at www.astm.org/JOIN.

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ASTM Committee E07 Next Meeting: Jan. 2529, 2015, Fort Lauderdale, Fla.

Technical Contact:
David Fry
Los Alamos National Laboratory
Los Alamos, N.M.
tel +1.5056652916
dafry@lanl.gov

ASTM Staff Contact:
Kathleen McClung
tel +1.610.832.9717
kmcclung@astm.org

ASTM PR Contact:
Barbara Schindler
tel +1.610.832.9603
bschindl@astm.org