Title :
Application of zero-phase digital filter in ultrasonic pressure measurement
Author :
Ling Zhangwei ; Liu Fujun ; Kong Shuai ; Qian Yueqiang ; Zheng Mulin
Author_Institution :
Zhejiang Provincial Special Equip. Inspection & Res. Inst., Hangzhou, China
Abstract :
Conventional methods for pressure measurement commonly require drilling a hole in the wall of the vessels, which usually lead to potential safety problems. It is meaningful to study a nondestructive pressure measurement method using ultrasonic technique. One of key problems in ultrasonic pressure measurement is to estimate the time delay of two ultrasonic pulses accurately. A general cross correlation method based on zero-phase digital filter was presented to improve the accuracy of time delay estimation. Ultrasonic critically refracted longitudinal wave was applied to measure the pressure. Ultrasonic signals contain the correlative noise, therefore, pre-filtering of signal was needed. Zero-phase digital filter which could effectively eliminate the phase distortion that caused by common digital filter was proposed to process the signals. Compared to Hilbert-Huang Transform, the experimental result shows that the general cross correlation method based on zero-phase digital filter is more stable and simpler.
Keywords :
correlation methods; delay estimation; digital filters; distortion; pressure measurement; ultrasonic measurement; correlative noise; cross-correlation method; nondestructive pressure measurement method; phase distortion elimination; signal pre-filtering; time delay estimation; ultrasonic pressure measurement; ultrasonic pulse; ultrasonic signals; zero-phase digital filter; Acoustic measurements; Acoustics; Correlation; Delay effects; Digital filters; Pressure measurement; cross correlation; pressure measurement; time delay; ultrasonic; zero-phase digital filter;
Conference_Titel :
Electric Information and Control Engineering (ICEICE), 2011 International Conference on
Conference_Location :
Wuhan
Print_ISBN :
978-1-4244-8036-4
DOI :
10.1109/ICEICE.2011.5778038