Thickness Measurement of Thin Layer by Ultrasonic Based on the Wavelet Transform Modulus Mazima
The use of ultrasonic to detect the thickness of the material has been extensively studied and the pulse-echo method is used more generally. Ways to deal with the requirements of the received signal, in the same interface at each time-domain reflection wave are separable, which calls for the launch signal is less than the duration of ultrasound at the same level and from the dissemination of media time or space launch signal the continuing length of less than twice the sample thickness. Therefore, the method used to deal with thin-layer material characterization issues, required the use of the ultrasonic frequency must be very high. However, the actual ultrasonic frequency at 20MHz or less, while the thin-layer thickness in the micron scale, it can not meet the requirements resulting in the pulse-echoes superposition, which are not easily distinguishable. In this paper, wavelet transform modulus maxima method of ultrasonic echo signals is used to detect the singular points. It overcomes the traditional echo superposition which can not be separated form defects. Thin-layer thickness measurement method is obtained.
Wavelet Transform Modulus Mazima Thickness Measurement by Ultrasonic Thin Layer
ZHOU Hailin LIU Meiquan ZHANG Yun LI Jianzeng
Ordnance Engineering College, Shijiazhuang, China, 050003
国际会议
第八届国际测试技术研讨会(8th International Symposium on Test and Measurement)
重庆
英文
1191-1194
2009-08-01（万方平台首次上网日期，不代表论文的发表时间）