SU685931A1 - Method of absolute graduation of hydrophones - Google Patents

Description

one

The invention relates to the field of hydroacoustic measurements and can be used to measure the absolute sensitivity of a hydrophone.

There is a method of measuring the absolute sensitivity of a hydrophone by the compensation method, based on the compensation of sound pressure forces on a sensitive element caused by electrical excitation of the radiator, and forces caused by electrical excitation of the null organ 1.

The closest technical solution to the invention is a method of absolute calibration of a hydrophone, based on the emission of sound waves, their reception and measurement of the electromotive force at their outputs 2.

The aim of the invention is to improve the accuracy of the hydrophone calibration process.

This is achieved by the fact that in the method of absolute graduation of a hydrophone, based on the emission of sound vibrations, receiving them calibrated by a hydrophone and a sensitive element and measuring the electromotive force at their outputs, the sound oscillations are also emitted by the zero-body, measure its excitation current the value at which the amplitude of the electromotive force at the output of the sensing element is equal to the value of the electromotive force at its output previously measured and the magnitude of the zero-organ excitation current and measured the magnitude of the electromotive force at the output of the graduated hydrophone is made to its graduation.

The drawing shows a functional diagram of the device that implements the proposed method.

In the device, the generator 1 is connected to the switch 2. One of the outputs of the switch is connected via an attenuator 3 to the electrical input of the zero-organ 4, and the second output is connected to the radiator 5.

Capacity C is included in the zero-organ excitation circuit. Outputs of sensing element 6, graduated hydrophone 7 and ps-tangential point (relative to the ground) of capacitance C

connected through a switch 8 with a measuring device (voltmeter) 9, acoustic communication is shown by a dotted line.

Calibration is carried out as follows.

From the excitation generator 1, through the switch 2, the radiator is electrically excited and, using switch 8, is measured with a voltage meter 9 at the output of the calibrated hydrophone 7 and the voltage at the output of the sensing element b. Then, by setting switch 2 to the power position of the null organ 4, the latter is electrically energized. Using an attenuator 3, the excitation current of the null organ 4 is changed until the voltage at the output of the sensitive element b, measured by a © using a voltmeter 9, is equal to the voltage at the output of the sensitive element at the previous measurement. After that, using a voltmeter 9 and a switch 8, the voltage U is measured on the capacitor C. The measured voltage U is related to the current

3 zero-organ excitation ratios

3 WCU, where Vf is the graduation frequency.

The proposed method favorably differs from the known need to measure in the course of calibration only the amplitude of the current of the electric excitation of the null organ, i.e. simpler calibration procedure, which greatly simplifies the automation of the latter and improves accuracy.

Claims (2)

1.Bobber R. Hydroacoustic measurements, Mir, 1974, p. 2. Golenkov A.P., Pavlov L.E. Absolute graduation of measuring hydrophones in the range of sound frequencies / - Measuring equipment, No. 5, 1967.