ASTM E746 PDF

1.1 This standard provides a practice whereby industrial radiographic imaging systems may be comparatively assessed using the concept of relative image quality response (RIQR). The RIQR method presented within this practice is based upon the use of equivalent penetrameter sensitivity (EPS) described within Practice E1025 and subsection 5.3 of this practice. Figure 1 illustrates a relative image quality indicator (RIQI) that has four different plaque thicknesses (0.015, 0.010, 0.008, and 0.005 in.) sequentially positioned (from top to bottom) on an absorber plate of a specified material and thickness. The four plaques contain a total of 14 different arrays of penetrameter-type hole sizes designed to render varied conditions of threshold visibility when exposed to the appropriate radiation. Each “EPS” array consists of 30 identical holes; thus, providing the user with a quantity of threshold sensitivity levels suitable for relative image qualitative response comparisons. There are two standard materials (steel and plastic) specified herein for the RIQI and absorber. For special applications the user may design a non-standard RIQI-absorber configuration; however the RIQI configuration shall be controlled by a drawing similar to Fig. 1. Use of a non-standard RIQI-absorber configuration shall be described in the user's written technique and approved by the CEO.