SU1317280A1 - Meter of displacements - Google Patents

Abstract

This invention relates to a measurement technique. The aim of the invention is to improve the accuracy when measuring dynamic movements by eliminating fluctuations of the light flux. Moving the object 3 causes a change in the initial gap between the end of the light guide 2 and the reflecting surface of the object 3, which leads to a change in the luminous flux coming from the source 1 through the transmitting light guide lines of the light guide 2 to the reflecting surface and then, after reflection falling through the receiving light guide to the photodetector. The luminous flux at the output of the light guide 2 contains a constant and variable components. The constant component of the light flux corresponds to the size of the gap Sg, and variable - to the value of dynamic displacements. The signal from the output of the photodetector 5 is fed to the registering device 7, and the registering device 11 controls the gap by measuring the ratio of the average levels of light fluxes at the input and output of the light guide 2. The stabilizer 9 stabilizes the average level of the light flux at the output of the light guide 2. f-ly, 1 ill. i cl f 74.

Description

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The invention relates to a measurement technique and can be used for non-contact measurement of dynamic movements in a wide frequency range.

The purpose of the invention is to improve the accuracy when measuring dynamic movements due to stabilization of the light exclusion of fluctuations of the light flux.

The drawing shows a block diagram of the meter.

The displacement meter contains a light source 1 installed at the end of the transmitting light lines (at the input of the light guide 2). Light guide 2 contains transmitting and receiving light lines. The ends of the light lines, directed to the reflecting surface of the moving object 3, are mechanically connected into a single structure and form the measuring end of the light guide. The measuring end is installed with a gap Sg at the reflecting surface using a holder 4 containing a micrometer screw. At the end of the receiving optical lines (at the output of the light guide 2) a main photodetector 5 is connected through a high-pass filter 6 to the recording device 7 (dynamic movements), the photoreceiver 5 also through the low-pass filter 8 is connected to the stabilizer 9 of the luminous flux and the inverting input of the operational amplifier 10 (OU). The output of the op-amp 10 is connected to the recording device 11 (static displacement.). The non-inverting input of the op-amp 10 is connected to a reference photodetector 12 mounted at the light source. Between the light source 1 and the reference photoreceiver 12 a diaphragm 13 is placed. In the light-flow stabilizer 9, the inverting input is connected to the divider 14 of the reference voltage.

The meter works as follows.

The luminous flux from the light source 1 through the transmitting light guide lines of the light guide 2 hits the reflecting surface of the moving object 3, where, reflecting through the receiving light lines of the specified light guide, hits the photodetector 5, the Holder 4 sets the initial gap Sj,, using the micrometer screw From the output of the photodetector 5 through the filter 6 high-end variable

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the component, corresponding to the magnitude of the dynamic displacements, enters the recording device 7. Also from the output of the photodetector 5 through the filter

The 8 low frequencies are variable component corresponding to the noise and the constant component corresponding to the average level of the light flux is fed to the stabilizer 9 of the light

flow. As a result of stabilization, the inverting input of the operational amplifier 10 through the filter 8 receives a constant component corresponding to the average level of the stabilized light flux at a given initial gap between the reflecting surface and the measuring end of the fiber. The inverting input of the shelter 10 receives a signal from the output of the photodetector 12, corresponding to the level of the light flux of the light source at the input of the light guide. From the output of an op-amp 10 signal proportional to the ratio of the light fluxes at the input and output

the fiber goes to the registering device 11 static displacements. The zero setting of the device 11 at a given initial gap is made by means of the diaphragm 13 by blocking part of the luminous flux entering the photodetector 12 from the light sources. Change the diaphragm to achieve: equality of the light fluxes falling on the photodetectors 5 and 12.

35 When measuring dynamic displacements in the event of a change in the initial gap S Q, it is corrected (setting the gap to a given value Q), Monitoring the value of the gap

40 are produced at the registering device 11.

Calibration of the meter is carried out by changing the gap by a specified amount of & S. In this case, a voltage, proportional to the value of the specified static displacement, is supplied to the input of the recording device 11. Dynamic displacements of the same magnitude correspond to the readings of instrument 7.

50 By adjusting the gain of the instrument 7 measuring the dynamic displacements, the deflection of the pointer of the instrument is achieved by an amount equal to the deflection of the pointer of the instrument 11,

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Claims (2)

Invention Formula 1. A displacement gauge containing a light guide made in the form of a packet of transmitting and receiving light guides, a luminous flux stabilizer whose output is connected to a light source, a photodetector, a recording device and a differentiating unit, which is designed to increase the accuracy measuring dynamic displacements, it is equipped with a diaphragm, an operational amplifier and a reference photodetector, the differentiating unit is made in the form of low and high pass filters, the main photodetector is installed at the receiving end2. Meter according to claim 1, characterized in that the stabilizer of the luminous flux is made in the form of an operational amplifier and divider light guides and connected respectively through a high-pass filter of the 15fire voltage, non-inverting to the recording device, and through the input of the operational amplifier the low-pass filter is stabilized to the input of the low-pass filter, and the luminous flux inverter and inverting input - to the divider of the supporting rudiyu input of the operational effort-voltage. Editor K. Voloshchuk Compiled by E.Glazkova 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 - 5 O13172804 The optical transducer and the reference photodetector are optically connected to the light source, the reference photodetector is connected to the non-inverting input of the operational amplifier, the output of which is connected to the recording instrument, and the aperture is placed between the light source and the reference photoreceiver. 2. A meter according to claim 1, characterized in that the stabilizer of the luminous flux is made in the form of an operational amplifier and divider the reference voltage, the non-inverting input of the operational amplifier is connected to the low-pass filter, and the inverting input is connected to the reference voltage divider.