The standard facility for the transmission the unit of sound pressure at ultrasonic frequencies

Abstract

Information is provided on a standard facility for calibrating hydrophones at frequencies from 100 kHz to 3 MHz, which created to expand the frequency range of the State primary standard GET 55-2017 to the area of high-frequency ultrasound. The actuality of the standard facility creation is justified. The possibilities of measurements and operation principles of the facility are briefly reviewed. The requirements to the characteristics of ultrasonic transducers are discussed. When selecting standard transducers, priority was given to their temporal stability, since the unevenness of the transducer frequency response is not of fundamental importance when calibrating using a tone signal. To reduce the influence of directivity, a precision four-coordinate positioning system of transducers applies, which including the control of transducers mutual position using laser beam. Attention is paid to the problems related with the mastering of higher frequencies.