Ultrasonic Thickness Measurement
Abbreviation: UTM
Non-destructive ultrasonic gauging of plate thickness to monitor wastage; required at intermediate / renewal class surveys.
In practice
Surveyors take 100s of readings during intermediate / renewal survey; locations dictated by IACS UR Z10 series. Persistent diminution beyond class-allowed wastage requires renewal.
Regulatory detail & full definition
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.
Authoritative source: IACS Unified Requirements ↗
Related
Source: IACS UR Z10.1, Z10.2, Z10.4, Z10.5
High confidence
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