High precision ultrasonic flow measurement based on a novel pulse-echo transceiver

Clamp-on flow measurement is widely used in various industrial applications due to its non-invasive and non-intrusive characteristics. However, improving the precision of transit-time difference clamp-on ultrasonic flowmeters is challenging, especially under low flow rate conditions. This article proposes a new type of clamp-on ultrasonic transceiver containing a single piezoelectric element, which can transmit and receive ultrasonic waves. A voltage amplitude difference (VAD) method is proposed for flow measurement based on the new transceiver. The vibration motion and electric response of the piezoelectric ceramic in bidirectional operation are analyzed. The experimental results indicate that the proposed method can reduce the combined uncertainty of flow measurement by 63 %, which significantly improves the flow measurement precision. Moreover, the clamp-on flowmeter using the VAD method only needs a voltage peak-hold circuit, a low-precision ADC and a simple MCU, instead of high-speed ADC and FPGA components used in the transit-time difference method.