The findings of an experimental program with the objective of evaluating the applicability and limitations of ultrasonic procedures currently used to characterize weld flaws are reported. The investigation also included other ultrasonic techniques not in general use but having potential application for determining the dimensions of weld flaws. The report contains recommendations for immediate application and suggests additional research that will be required for long-term improvements in current practice. The probe movement and time-of-flight techniques for defect through-thickness size measurement were subject to errors, although the time-of-flight tests gave significantly better results. These errors were such that in the case of probe movement up to 0.31 in. (7.9 mm) may have to be added to the measured size in order to be 95 percent sure that the actual flaw size did not exceed the measured value. For the time-of-flight technique the figure was 0.17 in. (4.3 mm). Operator variability increased the errors marginally for the probe movement tests only.
Abstract