The BPI is designed to yield quantitative information concerning neutron beam and image system parameters that contribute to film exposure, and thereby, affect overall image quality. For proper measurements of film exposure due to the neutron beam constituents, the BPI must be fabricated in accordance with this practice.

This practice shall be followed for the fabrication of all Beam Purity Indicators to be used with Method E 545 to determine image quality in direct thermal neutron radiography.

1.1 This practice covers the material and fabrication of a Beam Purity Indicator (BPI), which can be used to determine the relative quality of radiographic images produced by direct, thermal neutron radiographic examination.

1.2 The values stated in SI units are regarded to be standard.

1.3 This standard does not purport to address 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.