Data Acquisition for Steel Defect Detection using Continuous Wavelet Transform

Abstract

NDT UT (Non-Destructive Ultrasonic Testing) is essential for structural testing in steel to determine the condition of damage (hole defects) due to corrosion and long-term use. This research aimed to create a data acquisition system using CWT (continuous wavelet transform) and the results of the acquisition data were used to find the position of hole defects in steel. The data acquisition used pulse generator and amplifier. The signal from the pulse generator was used for the input of an ultrasonic transducer with amplitude of 60 Volts, a PRF of 1 kHz, and a pulse width of 1 µs. Meanwhile, the gain in the low noise amplifier was 28 dB that functions as a signal receiver for the ultrasonic transducer. The output signal from the ultrasonic transducer was processed using CWT to obtain the coefficient of approximation. The position of hole defects was based on the delta wave from the initial pulse and echo. Therefore, hole defects were indicated by a defect reflection wave. The acquisition system in this study was able to identify the location of hole defects in the steel. The average depth that could be detected was 0.79 cm with an error of 0.244 percent.