SU1493893A1 - Instrument pressure converter - Google Patents

Abstract

The invention relates to instrumentation engineering and makes it possible to increase the accuracy of pressure measurements by stabilizing the thermal mode of a power compensation coil. For this, along with the sensing element 1, connected with the lever 2, on which the error indicator 3 and the power compensation coil 5 and the amplifier 4 are fixed, the pressure transmitter contains two quadrants 9 and 10, the adder 11, the element of comparison 12, the source of the reference voltage 13 and an additional amplifier 14. The power compensation coil is made by a double wire in the form of two windings 6 and 7. When the measured pressure changes, the electrical circuit of the converter processes the signal from the error indicator 3, the transducer the magnitude of the measured pressure difference between the currents in windings 6 and 7, wherein the heat compensation coil power is maintained unchanged. This ensures the absence of thermal deformation of the windings 6 and 7, which leads to an increase in measurement accuracy. 1 il.

Description

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Igi bretna does not belong to instrument making II can be used in devices for measuring pressure of 1e11n with force compensation.

The aim of the invention is to improve measurement accuracy by stabilizing the thermal mode of the power compensation coil.

The drawing shows a diagram of the Converter.

Measuring the pressure transducer. Contains a sensitive jjie (bellows), lever 2, displacement indicator 3 an, amplifier 4, power compensation coil 5, made by a double wire in the form of two windings 6.7, found in the magnetic field of a permanent magnet 8 , quadrants 9, 10, adder M, reference element 12, reference source 13 and dogulnite. IA power amplifier.

The sensing element 1 is associated with a lever 2, on which the indicator 3 is fixed, and the coil 5 and the power compensation coil are not aligned. Amplifier A is connected by an input to the output of the error indicator, s; by a stroke - to the beginning of the winding 5, the end of which is connected to the T1 INPUT. Quadrator 9. The output of the additional amplifier 1A is connected to the 1 start of the winding 7, the end of which is connected to the input. of the square of the mouth 10. The outputs of the quadrants 9,10 are connected to the output to measure the pressure transducer i- mn:: with the corresponding; -:: inputs sum TC; i 11, the output connected to the first input of the comparison element 12, the second input of the last connected to iic; By the point of view 13 of the reference voltage, and: - with the input of the additional amplifier 1A.

Measuring pressure transducer E operates as follows.

In the absence of measured pressure on the windings 6.7, odic one currents flow, with magnetic flux of these windings equal to zero and there is no compensation. When pressure is applied to the input of the sensing element 1, the lever 2 deviates from its initial position, a voltage appears at the output of the error indicator 3, which leads to a difference in currents in the windings of 6.7 katui; ki 5 force compensation, and the sum of the squares of the currents windings 6,7 saved35

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This is due to the action of the control system formed by the elements 9, 1 O, I1, 12, 1 A.

The magnetic flux due to the resulting difference in the currents in the windings 6.7 creates on the lever 2 a compensation force corresponding to the measured pressure, therefore the output value of the device is the difference TOKdB of the windings 6.7.

Due to the fact that the power compensation coil 5 is double-driven, the resistance of winding 6.7 does not change when the currents flowing through them change, and the total heat release in the windings 6.7 remains constant. The condition teplovsgs. the power-on mode 5 of the power compensation ensures the absence of thermal deformations of the windings 6.7, which increases the accuracy of measurements. In addition, it is possible to increase the density of the currents and the windings 6.7 of the coil 5 force

Claims (1)

compensation, which makes it possible to increase the compensation force of presinion pressure measuring transducers. Invention Formula A pressure transducer containing a sensitive element associated with a lever on which the mismatch and power compensation indicator is mounted, and an amplifier whose input is connected to the output of the discrepancy indicator, characterized in that in order to improve the accuracy of the thermal the power compensation coil mode, it is equipped with two quadrs, an adder, a reference element, a reference voltage source and an additional amplifier, and the power compensation coil is made for nr-i is checked in the form of two windings, the beginning of these windings are connected respectively to the outputs of the amplifiers, their ends are connected respectively to the quad inputs, the first quad outputs are connected to the output of the measuring transducer and, the second quad outputs are connected to the corresponding inputs of the adder, the output the adder is connected to the input of the comparison element, the second input of which is connected to the source of the reference voltage, and the output to the input of the additional amplifier.