ASTM E803-91(2013) PDF

Scope: 4.1 The quality of a neutron radiographic image is dependent upon many factors. The L/D ratio is one of those factors and constitutes a numerical definition of the geometry of the neutron beam. The L/D ratio required for a specific neutron radiographic examination is dependent upon the thickness of the specimen and the physical characteristics of the particular element of interest. Use of this test method allows the radiographer and the user to determine and periodically check the effective collimation ratio.

1.1 This test method defines an empirical technique for the measurement of the effective collimation ratio, L/D, of neutron radiography beams. The technique is based upon analysis of a neutron radiographic image and is independent of measurements and calculations based on physical dimensions of the collimator system. The values derived by this technique should be more accurate than those based on physical measurements, particularly for poorly defined apertures.

ASTM E803-91(2013) Referenced Document

ASTM E1316 Standard Terminology for Nondestructive Examinations*， 2024-02-01 Update
ASTM E748 Standard Practices for Thermal Neutron Radiography of Materials*， 1995-04-20 Update

2020 ASTM E803-20 Standard Test Method for Determining the L/D Ratio of Neutron Radiography Beams
2017 ASTM E803-17 Standard Test Method for Determining the L/D Ratio of Neutron Radiography Beams
1991 ASTM E803-91(2013) Standard Test Method for Determining the L/D?Ratio of Neutron Radiography Beams
1991 ASTM E803-91(2008) Standard Test Method for Determining the L/D Ratio of Neutron Radiography Beams
1991 ASTM E803-91(2002) Standard Test Method for Determining the L/D Ratio of Neutron Radiography Beams
1991 ASTM E803-91(1996) Standard Test Method for Determining the L/D Ratio of Neutron Radiography Beams
1991 ASTM E803-91 Standard Test Method for Determining the L/D Ratio of Neutron Radiography Beams