SU1170266A1 - Device for measuring non-electrical quantities - Google Patents

Description

The invention relates to the field of electrical measurements of non-electrical quantities, in particular to the measurement of displacements, deformations, etc., and can be used for automatic control and regulation.

The purpose of the invention is to improve the measurement accuracy by automatically correcting the measurement result Yu in the form of reducing the error from the mutual instability of the frequency of the oscillators.

The drawing shows a block diagram of a device for measuring non-electrical quantities.

The device contains measuring 1 and compensation 2 sensors, the outputs of which are connected to the first and second inputs 20, respectively

the first switch 3, the first output of which is connected to the input of the first auto-oscillator 4, the second - with the input of the second auto-oscillator 5, the outputs of the auto-oscillators 4 and 5 are connected respectively to the first and second inputs of the second switch 6 ,. the first and second outputs of which are connected respectively with the first and second. with the inputs of the meter 7, the ratio of the frequencies that are connected to the input of the calculator 8, the first output connected to the recorder 9, and the second to the input of the control unit 10, the output of which is connected to 35

control inputs of the first 3 and second 6 switches.

The device works as follows.

Compensation sensor 2 set-40 flax with a fixed plunger.

Measurement is done in two>

tact In the first sensor 1 is connected to the first input of the meter 7 through 45

the first input and output of the switch 3, the auto generator 4, the first input and output of the switch 6. The compensation sensor 2 is connected to the second input of the meter 7 through the second input and output 50 of the switch 3, the auto generator 5 and the second input and output of the switch 6. In the meter 7 frequency ratio determine the ratio

2

ί 1 + 4- - frequency of the oscillator 4 with parameters q = b ₀ + eh frame of a circuit b-) C ₄ "- inductance iz- b measuring sensor 1} - increment induk- sensor 1 proportional measurable ^K 4 displacement; - the coefficient is unstable

frequency frequency introduced by the active elements of the oscillator 4 and the capacitance of the oscillating circuit (C ₊ );

from 1 ⁺ K 5

ΐ2 ~ - ^^ === - “frequency of the auto-oscillator 5 with the parameter frame of the circuit L ₂ C _y ,

where b ₂ . - inductance of the compensation sensor 2; .

Cd- is the coefficient of frequency instability introduced by the active elements of the oscillator 5 and the capacity of the oscillating circuit (C ₅ ).

The number is entered in the calculator

8. In the control unit 10, a command is generated which switches 3 and 6 are switched, measuring sensor 1 switches to the first input of meter 7 of the frequency ratio through the first input and second output of switch 3, the autogenerator 5, the second input and the first output of switch 6, and the compensation one The sensor 2 is connected to the second input of the frequency ratio meter 7 through the second input and the first output of the switch 3, the autogenerator 4, the first input and the second output of the switch 6. In the frequency ratio meter 7, the ratio is determined

Where

1+ cd

frequency

autogeny)

Rotor 5 with the parameters of the circuit L ^ Su;

55

3

1170266

g - 1 ⁺ * 4

'~-рТс ~ ^{frequency of the} autogenerator 4 with the parameters of the circuit 1 ^ 4 *

In calculator 8, the product is calculated.

Ν- = Ν N N = Ν

* ⁰¹² ° h '

(five)

- scale factor where Ν „= cГu X

nom

conversion rate;

- the discreteness of measurement of the ratio;

"U - sensitivity

measuring sensor;

ten

15

20

H _{no / L} is the nominal value of the measured value.

Simultaneously, the difference is calculated.

^and 2

where Ν _χβ = Ν _Χ (Σ <b _e ) is the result obtained for

‘P = 1> in and selected for the origin of the movement.

The resulting difference ΑΝ _Χ is output to the recorder 9. From (4) it can be seen that • the measurement result ΑΝ _{Χ is} linearly related to the sensor parameter and does not depend on the frequency instabilities of the oscillators 4.5.

Claims (1)

DEVICE FOR MEASURING NON-ELECTRIC VALUES, containing a series-connected measuring sensor, the first switch and the first oscillator, as well as a compensation sensor, a second oscillator, a frequency ratio meter and a recorder, characterized in that, in order to improve measurement accuracy, a second switch, a calculator and a control unit are inserted, the compensation sensor is connected to the second output of the first switch, the second the output of which is connected to the input of the second autogenerator, the outputs of the first and second autogenerators are connected respectively to the first and second inputs of the second switch, the first and second outputs of which are connected to respectively, with the first and second inputs of the frequency ratio meter, the output of this meter is connected to the input of the transmitter connected to the recorder by the first output, and the second to the input of the control unit, the output of which is connected to the third inputs of the first and second switches. . YU zi „„ 1170266 > one 1170266