SU782186A1 - Method and device for graduating acoustic receiver - Google Patents

Description

one

The invention relates to electromechanical transducers, and in particular to methods and devices for calibrating receivers of acoustic oscillations.

A device for calibrating acoustic receivers using an exemplary radiator and a method for performing such a calibration are known. This device contains an electrical signal generator, a measuring device and a model electroacoustic emitter. The calibration is carried out as follows. A signal from the generator is fed to a sample radiator and the values of the applied current or voltage are measured. The emf is then measured at the output of the calibrated receiver. The calculation of its desired sensitivity is carried out from the results of these measurements and the known sensitivity of the sample emitter in the radiation mode using the formula

p / Egp - where / D - sensitivity of the calibrated

receiver;

EG.P-EMF at the output of the calibrated receiver;

Ets TSC excitation of the reference emitter;

T - sensitivity of the exemplary radiator 1.

The disadvantage of this method and device for calibration is its low accuracy, especially when operating in a wide frequency range. In addition, the complex nature of the dependence of the sensitivity of the model radiator on the frequency significantly reduces the performance of the calibration, making it difficult to automate.

It is also known a device for calibrating an acoustic receiver containing a radiator made in the form of a quadrupole with an acoustic output connected to a calibrated receiver connected to a recording device and an electrical input connected to a signal generator 2 and 3.

The disadvantage of this device is 20 the complexity of automating the process of calibration and low accuracy, due to the known method of its implementation.

The purpose of the invention is to increase the accuracy and performance of calibration.

This goal is achieved by the fact that the emitter is made in the form of a six-port equipped with a second electrical input connected to the recording device and made with the possibility of a lawsuit. The exchange of energy with the first electrical input when the acoustic output is decelerated.

Using the proposed device, it is possible to carry out a method of calibrating an acoustic receiver, characterized in that the emf is measured at the second electrical input and the sensitivity of the calibrated receiver is determined by the formula

/ Ег.п К и,, - Ё7 f

where the mind is the sensitivity of the graduated

receiver; EG.P.-EMF output graduated at

an emnik;

Ej-EMF at the second electrical input of the radiator; K - constant emitter; H (g) Reciprocity parameter, defined for a particular spatial arrangement of the emitter and graduated receiver, and the boundary conditions of the acoustic medium;

f - graduation frequency. FIG. 1 shows one of the embodiments of the radiator; in fig. 2 is a block diagram of an installation for calibrating an acoustic receiver.

The emitter and the installation consist of a cylindrical piezoelectric shell 1, the external electrode of which is divided into sections 2 and 3. These sections are electrically connected through one and their terminals form two electrical inputs 4 and 5, and the outer surface of the shell 1 is working and forms an acoustic input acoustic receiver 6, which is located in the far acoustic field of the radiator 7.

When electrical excitation is applied to one of the inputs 4 or 5, the piezoelectric. Shell 1 oscillates in radial modes. When the working surface is completely braked, the excitation of any of the electrical inputs does not cause a voltage on the second electrical input.

The installation works as follows.

When the start signal is applied, block 8, which is a source of control voltage with a storage device, produces a monotonically increasing voltage from the zero input to the control input of the attenuator 9. From the output of this attenuator, which is supplied from the signal generator 10, increases in amplitude The excitation voltage is applied to one of the electrical inputs of the radiator 7. The latter acoustically excites the calibrated receiver 6 (the acoustic connection is shown by a dotted line). Appearing at the second electrical input of the radiator 7, the EMF is fed to the input of the comparator AND, where it is compared with a voltage of a stable level. When equality of this voltage and the aforementioned EMF is reached, the comparator produces a control signal of the block 8. By this signal, the growth of the control voltage of block 8 stops and its level is remembered and kept constant for the time required to register the sensitivity value of the tested receiver. The sensitivity value is formed in accordance with the algorithm for the free field of the emitter from the output emf of the graded receiver using two integrators 12 and 13, each of which divides the amplitude of the input monochromatic signal by the value of its frequency. The value of the quotient from dividing said EMF by the square of the frequency is recorded by the recorder 14 by the same control signal produced by the comparator. Upon completion of the registration of this level, equal in a certain

S to the scale of the sought sensitivity of the calibrated receiver, the recorder 14 transmits a graduation signal to block 8, after which the control voltage of the source of block 8 decreases to zero and the installation retains this ready state to the next Start signal.

The advantage of the proposed device and method is that it is not necessary to determine the frequency dependence of the sensitivity of the radiator in the working range.

y frequencies - it is enough to calibrate the emitter at one frequency to determine the constant K. At the same time, possible instabilities of the radiator are automatically taken into account when performing each calibration by changing the value of E, which ensures higher accuracy of calibration.

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Claims (3)

 1. A device for calibrating an acoustic receiver, comprising an emitter made in the form of a quadrupole with an acoustic output connected to a calibrated receiver connected to a recording device and an electrical device o an input connected to a signal generator, characterized in that, in order to increase the accuracy and performance of the calibration, the emitter is made in the form of a six-port equipped with a second electrical input connected to the recording device and configured to exclude the exchange of energy with the first electrical input when the acoustic is decelerated output 2. A method for its implementation according to claim 1, characterized in that the emf is measured at the second electrical input and the sensitivity of the calibrated receiver is determined by the formula (r) where) M - sensitivity of the calibrated receiver; EG.P.-EMF output graduated at an emnik; ES EMF on the second electrical input de radiator; K - constant emitter; - a reciprocity parameter defined for a specific spatial location of the radiator and graduated receiver and the boundary conditions of the acoustic medium; t frequency graduation. Sources of information taken into account in the examination I. Called K. Graduation and calibration of phonos. “Equipment and weapons, 1972, 5. 2. USSR author's certificate 241804, class 42 S 1/00, 1967 (prototype). 3.Bobber R. Hydroacoustic measurement, M., “Mir, 1974, p. 34 (prototype).