The development of a shock-tube based characterization technique for air-coupled ultrasonic probes.

The present paper proposes a new characterization technique for air-coupled ultrasound probes. The technique is based on a shock tube to generate a controlled pressure wave to calibrate transducers within their operating frequency range. The aim is to generate a high frequency pressure wave (at least up to 200 kHz) with the low energy levels typical of commonly used air-coupled ultrasound probes. A dedicated shock-tube has been designed and tested to assess calibration performances. The sensor transfer function has been measured by using a pressure transducer as reference.