Interferometric calibration and accuracy determination of a wide band standard acoustic source
For safety reasons hydrophones are used increasingly to measure the ultrasonic pressure generated by instruments used in the medical field. Because of ageing, these hydrophones have to be calibrated periodically. For this purpose a standard acoustic source has been developed which allows this calibration to be performed very quickly. The main element of this source is a thick disk of monocrystalline lithium niobate with a large diameter. The interferometric measurement of the displacement on the generated wave front is described and the difference between the actual generated pressure step and the ideal one is given as a function of frequency. The influence of any error source is assessed, leading to an accuracy within +/- 2 % below 4 MHz. The error increases as the square of the frequency above 4 MHz and reaches 5 % at 10 MHz and 20 % at 20 MHz.
Bibliographic Reference: Paper presented: Ultrasonic International '93, Vienna (AT), July 6-8, 1993
Availability: Available from (1) as Paper EN 37643 ORA
Record Number: 199311035 / Last updated on: 1994-11-29
Original language: en
Available languages: en