Uncertainty Evaluation on Weld Defect Depth Inspected by Ultrasonic

The uncertainty sources for measuring weld defect depth by ultrasonic method were analyzed according to GUM method, and the measurement uncertainty was evaluated. The results indicate that the uncertainty sources for ultrasonic testing of weld defect depth included horizontal linear error of ultrasonic fault detector, property of the angle probes and specifications of the check block. In order to obtain accurate test results, it is indispensable to examine the horizontal linear error of ultrasonic fault detector and make sure that the error is kept in an appropriate range. And the suitable probe and test block are also necessary.