SU668104A1 - Method of absolute calibration of electroacoustic transducer - Google Patents

Description

np. - acoustic resistance of the null organ from the medium in the reception mode T - sensitivity of the null organ in the radiation mode; and the excitation voltage of a null organ. The method is based on the trace) lean. With the same output signals of the sensitive element, which is either under the influence of the acoustic field of the radiator, or under the influence of the piezoelectric forces of an electrically excited zero body, the moduli of displacements of the surface of the sensitive element are equal. A-i aix-iJr e-. rigid mechanical connection of the sensor Woro of an element and a il-organ and the relatively low value of the ratio of the thickness of the latter to its radius of displacement of the surfaces of the nullorgan and the sensitive element can be considered the same. The mentioned equality / moduli of displacements is accompanied by the equality of the moduli of the velocities of the surface of the zero-organ; where is the velocity of the surface of the null organ under the action of its excitation from the electrical side; Vnp, is the velocity of the surface of the null organ under the action of excitation by its external acoustic field. A created emitter, rad can be represented as follows: PuM-S is the sound pressure generated by the null organ upon excitation from the electrical side; - acoustic resistance of the null-organ to medium; S is the surface area of the null-organ emission (reception). Vnp can be represented as follows:% pr

where Rpr - sound pressure on the null-organ created by the emitter; Zjip is the acoustic resistance of the null organ from the medium in the reception mode.

Let us express RELF through the excitation voltage of the null organ U and its sensitivity in the radiation mode G:

P w futfl -

m

where EEL is the electrical impedance of the null organ. From (1, 2, 3, 4) we have:

l ..

- / V

f

Zy

uta

  T

sensitivity,

acoustic resistance of the null-organ radiation into the medium; electrical zero-body impedance; EMF at the output of the calibrated transducer;

acoustic resistance of the null organ from the medium in the reception mode; null organ sensitivity mode

Claims (2)

radiation; zero-body excitation voltage. If a null organ is used at frequencies below its resonance, then it’s possible to consider Znp and Z3ji as proportional, and 2y and G as proportional f, where f is frequency. Therefore (5) can be represented as follows; .-K-U, (6) where K is a constant coefficient, independent of frequency and equal to; v- f, X L% from IM Designating E EMF at the output of the calibrated hydrophone, caused by the acoustic field of the emitter, we obtain an expression for calculating the sensitivity M in the receiving mode of the calibrated hydrophone: From the foregoing, a clear connection of the new operations organ and equalization at this time. EMF at the output of the sensing element) with the simplification of the calibration procedure (the need to change the amplitudes of the electrical excitation of the null organ). The invention is a method of absolute calibration of an electroacoustic converter based on the excitation of a radiator and a null organ, characterized in that, in order to simplify the procedure of calibration, the operator first electrically excites and emf at the output of the sensitive element and at the output transducer, remove the electrical excitation of the radiator and electrically excite the zero-body voltage, at which the EMF at the top of the primary element is equal to the value of its output sensing zlementy ceiling elements at the previous measurement, and ztom measured voltage electrical energization Null body, and the sensitivity of the transducer is determined by the formula: Sources iiforma11ii, received in vyupmanye under examination 1. bobber R. hydroacoustic measurement. World, M., 1974, p. 60-63. 2. Goleikov A.N., and Pavlov L.E., Absoluhy Graduation: Measuring Hydrophones in the Sound Frequency Range. Journal Measuring equipment, N 5, 1967.