SU1317278A1 - Device for measuring linear displacements - Google Patents

Abstract

This invention relates to a measurement technique. The aim of the invention is to improve noise immunity and sensitivity. In the device, by dividing the output voltage of the phase meter connected to the interdigital transducers (IDT) of the mobile receiving piezoplate, by the output voltage of the frequency detector connected to the surface acoustic wave generator (SAW), the effect of temperature on the measurement result is eliminated . 1 il.

Description

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The invention relates to a measurement technique and can be used to measure displacements.

The aim of the invention is to increase noise immunity and sensitivity by eliminating temperature errors.

The drawing shows a device for measuring linear displacements.

The device for measuring linear displacements contains the first radiating and intended for connection with the object the mobile receiving piezo-plates 1 and 2, the first and the second interdigital transducers 3 and 4, each of which is located at opposite ends of the working surfaces of the corresponding piezoplates 1 and 2, absorbers located at the ends of the piezoplates 1 and 2 (not indicated in the drawing), the first wear-resistant cavities 5, fixed on the receiving piezoplates 2, the third counter-to-pin converter b, fixed c at the opposite end of the working surface of the first radiating piezoplate 1, the fourth counter-whip transducer 7, mounted on the opposite end of the second working surface of the receiving piezoplate 2, the second similar radiating piezoplate 8 with absorbers (not marked in the drawing) and the second wear-resistant strips 9 mounted on opposite ends of the working surface of the second radiating piezoplates 8th and fifth of the interdigital transducers 10 and 11, the amplifier 12, the phase meter 13 and the recorder 14 The frequency detector 15 and the voltage divider 16 are connected in series with a second input connected to the output of the phase meter 13, the first input of which is connected to the output of the second interdigital transducer 4, the second input to the output of the fourth interdiaptic converter 7, output connected to the input recorder 14, the amplifier 12, the input is connected to the red and fifth interdigital transducers 3 and 10, the output to the third and sixth interdigital transducers 6 and 11, forming a surface acoustic generator their wave (SAW) Provided compound amplifier 12 to a generator start-up (not shown in the drawing).

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A device for measuring linear displacements operates as follows.

The launch generator through amplifier 12 excites the third and sixth transducers 6. And 11. The surface acoustic waves, propagating in the first and second radiating piezo plates 1 and 8, excite surfactants on the working surfaces of the mobile receiving piezoplates 2, which are adopted by the second and fourth anti-pin converters 4 and 7. Electrical signals from the latter are fed to the inputs of the phase meter 13. The output signal of the phase meter 13 is fed to the second input of the divider 16, to the first input of which the output signal is supplied deleterious detector 15 proportional to the value of ny SAW oscillator frequency. The output signal of the divider 16, proportional to the displacement of the receiving piezoplate 2, is recorded by the recorder 14.

Under the action of interference, for example, when the temperature changes, the linear dimensions of piezoplates 1.2 and B change, which causes, in particular, a change in the distance L between converters 3, 6 and 10, 11 and, accordingly, changes in the surfactant phases propagating in the receiving piezoplate 2, as well as the change in the frequency of the generated surfactants.

When the SAW generator frequency changes, for example, it doubles, the output voltages of the phase meter 13 and the frequency detector 15 also double, and the spin voltage of the divider 16 remains unchanged.

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Claims (1)

Invention Formula A device for measuring linear displacements, containing radiating and intended for connection with an object mobile receiving piezoplates, the first and second interdigital transducers, each of which is located at opposite ends of the corresponding working surfaces. piezoplates, absorbers located at the ends of piezoplates, wear-resistant strips attached to the receiving piezoplates, generator, phase meter, first input connected to the second interdigital transducer, and registrar, for the purpose of improving noise immunity and sensitivity it is equipped with a third interdigital transducer, mounted on the opposite end of the working surface of the radiating piezoelectric plate, fourth interdigital transducer, mounted on the counterhole At the end of the second working surface is the receiving piezoelectric plate, the second one is similar to the radiating piezoplate with absorbers and wear-resistant strips located symmetrically with the first radiating piezoelectric plate from the side of the second working surface of the receiving piezoplate. mounted on the opposite end of the amplifier. 5 fO 5 172784 The working surface of the second radiating piezoplate is the fifth and sixth counter-pin converters connected in series with a frequency detector and voltage divider, the second input connected to the output of the phase meter, the second input of which is connected to the fourth counter-pin converter, and the output to the recorder, amplifier the input is connected to the first and fifth counter-pin converters, the output is connected to the third and sixth counter-pin converters and forming the SAW generator with them, and the input -frequency detector is connected to you at Editor K. Voloshchuk Compiled by G. Ryzhakov Tehred A. Kravchuk Proofreader A.Zimokosov Order 2412/36 Circulation 677 Subscription VNIIPI USSR State Committee, for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4