Includes requirements for preparation of test surfaces and for establishing scanning sensitivity and describes two procedures for determining attenuation and for sizing of discontinuities located. Quality levels are classified in terms of four zones of influence within a casting. Appendices cover purchasing guidelines, factors affecting probe selection, methods for determination of attenuation and transfer losses, guidance on the nature of discontinuities, their location and identification, procedures for sizing using the 20 dB intensity drop method, use of reflectivity diagrams and compensation for curvature.