High frequency air-coupled ultrasound measurement with the flexural ultrasonic transducer

The flexural ultrasonic transducer consists of a piezoelectric ceramic bonded to an edge-clamped metallic membrane, and is used for both generation and detection of ultrasound waves. It is typically employed for proximity measurement and for flow measurement in gases and liquids. The conventional industrial applications of flexural ultrasonic transducers typically utilise resonance frequencies in the region of up to around 50 kHz, but strategies must be developed to address the increasing demands of contemporary technology. Ultrasound measurement at higher frequencies than those typical of flexural ultrasonic transducers which are currently available is desirable in applications relating to gas and water metering in petrochemical, district heating, and power industries. In this study, the measurement of high frequency ultrasound waves in air through the exploitation of different modes of the flexural ultrasonic transducer is achieved using another as a detector supplied by a suitable amplifier circuit. This investigation represents notable development in widening the industrial application potential of the flexural ultrasonic transducer.