SU505902A1 - Sound speed sensor in water - Google Patents

Description

one

The invention relates to devices for converting electrical voltage to ultrasonic vibrations and vice versa, in particular, to piezoelectric ultrasonic transducers, and can be used to measure the speed of sound in water during hydrophysical studies.

Devices for measuring the speed of sound in water are known in which sensors are used with a liquid hydrostatic pressure compensator.

A disadvantage of the known sensor is the complexity of the design, low reliability and stability of the measurements. These drawbacks are associated with the presence of a liquid compensator in the sensor, whose normal operation in the operation process is disturbed due to possible leakage of liquid, which leads to a decrease in the accuracy and stability of measurements during long-term deep-water hydrophysical studies. In addition, the reliability of the sensor is reduced due to the insufficient strength of the piezoceramics pening unit with all kinds of external mechanical effects.

The purpose of the invention is to improve the accuracy of measurements.

For this purpose, in the proposed sensor, the compensator is made in the form of a solid metal rod electrode with an upper

part in the form of a truncated cone, isolated from the sensor body. On the end surface of the pripus electrode, a disk-shaped piezo-ceramic, zash, is searched for with a thin layer of sound-permeable material, which, along with airtightness, protects the piezoceramics from the external environment. The proposed design makes it possible to preserve piezoceramics from destruction at high hydrostatic pressures, to dramatically increase the reliability of the sensor and the measurement stability during long-term studies at sea.

The invention is illustrated in the drawing, which schematically shows the proposed sensor.

In case 1 of the sound speed sensor there is an electrode 2, isolated from the case

sleeve 3, 4. On the end surface of the electrode napa on piezoceramics 5 disk form. The outer lining of the piezoelectric ceramics is connected to the sensor body by a jumper b and the transmitter with a sound-permeable coating.

7, which ensures the tightness of the sensor. The base 8 with the reflector 9 and the lock nut Y is attached to the sensor housing by means of a threaded connection. In this sensor design, the terminal 11 for supplying ultrasonic frequency voltage will be inside the container, therefore there is no need to ensure the tightness of the sensor housing from the terminal side.

The sensor works on the principle of a cyclic sound velocity meter in water. Voltage pulses are applied to electrode 2, which are converted by piezo-ceramics 5 into ultrasonic pulses propagating in water towards the reflector 9. Reflected ultrasonic pulses are again fed to piezo-ceramics, converted into electrical signals and recorded by a measurement circuit. The speed of sound is determined by the known ratio, which takes into account the propagation time of the ultrasonic pulse in water and the length of the base.

Claims (1)

Invention Formula A sensor of sound speed in water, comprising a housing, piezoelectric ceramics, a compensator, a base and a reflector, characterized in that, in order to improve measurement accuracy, the compensator is made in the form of a solid metal rod electrode with a truncated conical upper part, to the end of which is attached piezoceramics . ABOUT