his International Standard establishes the procedures for measuring performance characteristics of components of pulse-echo ultrasonic non-destructive testing instruments including both analog and digital type instruments with screen displays. The aim is to establish uniformity of evaluation techniques, to form a basis for data correlation and for interpretation of results obtained from different laboratories and at different times. Note that this International Standard establishes no acceptance criteria; such criteria should be specified by user parties. The usual components of ultrasonic non-destructive testing instruments and the performance characteristics for which procedures for measuring these characteristics are included