Research on Wireless Passive Ultrasonic Thickness Measurement Technology Based on Pulse Compression Method

Fixed-point thickness measurement is commonly used in corrosion detection within petrochemical enterprises, but it suffers from low detection efficiency for localized thinning, limitations regarding measurement locations, and high equipment costs due to insulation and cooling layers. To address these challenges, this paper introduces a wireless passive ultrasonic thickness measurement technique based on a pulse compression algorithm. The research methodology encompassed the development of mathematical and circuit models for single coil and wireless energy transmission, the proposal of a three-terminal wireless energy mutual coupling system, and the establishment of a finite element model simulating the ultrasonic body wave thickness measurement and wireless energy transmission system. An experimental setup was constructed to conduct thickness measurements on metal samples varying in thickness, shape, and material composition. The experimental findings revealed that the wireless ultrasonic echo signal, when processed using the pulse compression algorithm, achieved a thickness measurement accuracy approximately ten times superior to that of the untreated echo signal. This significant improvement in accuracy facilitates the high-density deployment of thickness measurement points in petrochemical applications.