DefinePK

Abstract

In ultrasonic non-destructive tests, transducer is one of the most part need to determine carefully. The attenuation behavior of transducer will impact overall ultrasonic measurement accuracy base on signal processing analysis. In normal applications, ultrasonic inspector relies on transducer calibration result produced by the manufacturer where there are no doubts to question the accuracy of measurement results. However, the attenuation behavior of transducer can be defined based on signal-to-noise ratio (SNR) value. In this paper, the attenuation behavior of ultrasonic transducer was investigated based on SNR value through signal filtering approach. Since the detection of flaw in composite laminates using ultrasonic non-destructive testing (NDT) approach is highly complex due to noise occurrences, several types of filter were applied and compared each other in order to propose the suggested filter base on SNR result. A 2.25 MHz single crystal immersion transducer is used to perform ultrasonic scanning for composite laminates material which is thickness up to 7.4 mm with scanning rate 7.50 mm/sec under lab condition. As a comparison result, when applying discrete wavelet transform (DWT) de-noising approach, SNR was enhanced and caused defect detection was easily identified.