ON ULTRASONIC FLAW DETECTING METHOD

On the Calibration of Ultrasonic Flaw Detector

For the assessment performance of the ultrasonic flaw detector (UFD) equipment, various standard documents are referred to such as ASTM (E317), British Standard (BS-4331), Bureau of Indian Standard (IS-12666), and more. The methods of calibration are spelt in different tone in these documents while broadly serving the same purpose. In the present paper a comparison for the calibration procedure...

Ultrasonic Flaw Detection in Ceramics

Maximum nongaussianity principle for ultrasonic flaw detection

Maximum nongaussianity principle for ultrasonic flaw detection Hua-ming LEI, Wei LIANG, Pei-wen QUE Department of Instrument Science and Engineering, Shanghai Jiaotong University, Shanghai, 200240, P.R.China E-mail: [email protected] Abstract: The noise suppression techniques with wavelet transform (WT) are widely used in non-destructive testing and evaluation (NDT&E). In this paper, we have an...

Study on Feature Extraction and Classification of Ultrasonic Flaw Signals

One of the most important techniques of ultrasonic flaw classification is feature extraction of flaw signals,which directly affects the accuracy and reliability of flaw classification.Based on the non-stationary characteristic of ultrasonic flaw signals, a new feature extraction method of ultrasonic signals based on empirical mode decomposition (EMD) is put forward in the paper. Firstly, the or...

A MEMS Transducer for Ultrasonic Flaw Detection

Metal structures can fail because of fatigue crack propagation or because of section loss from corrosion. Regular inspection is required to intercept such failures, and in situ sensors would be a superior technology for that purpose. We have designed and fabricated arrays of MEMS capacitive diaphragm transducers and we report on their performance as pulse-echo detectors in direct contact with s...