The evaluation of small area membrane hydrophones
The aim of the project was to develop and then to evaluate the performance of small area membrane hydrophones with particular attention to their suitability for characterising medical diagnostic ultrasonic fields. NPL was responsible for the evaluation of the acoustical performances of the devices. Both frequency and directional responses were measured up to 30 MHz and compared with theoretical models. The hydrophones had active diameters of 0.2 and 0.1 mm when determined from the directional responses. Finally, the hydrophones were used to characterise the fields from three medical diagnostic transducers and the results compared with those using membrane hydrophones with larger active elements. In one case, a 0.5 mm diameter hydrophone measured only 25% of the true pressure as a result of spatial averaging over the active element. In the same field the 0.1 mm diameter hydrophone measured over 87% of the true pressure.
Bibliographic Reference: EUR 12371 EN (1990) 58 pp., MF, ECU 4
Record Number: 199010169 / Last updated on: 1994-12-01
Original language: en
Available languages: en