Ultrasonic Thickness Measurement

Ultrasonic Thickness Measurement — non-destructive gauging of plate, frame, and stiffener thickness using calibrated ultrasonic instruments to monitor wastage. UTM is required at intermediate and renewal class surveys per IACS UR Z10.1, Z10.2, Z10.4, and Z10.5 with prescribed numbers and locations of readings. Operators must be qualified per IACS UR Z17 and the firm approved by class. The gauging report is submitted to class for evaluation; substantial corrosion (over a defined diminution) requires renewal of plating before the certificate can be endorsed.