SU384075A1 - COMPENSATION DEVICE FOR OPERATION OF RESISTANCE CENTER - Google Patents

Description

I

The invention relates to the field of measurement technology and can be used to monitor non-electric values using resistance sensors that have a quadratic dependence of resistance on a monitored parameter, for example, to measure temperature using platinum resistance thermometers.

Compensation devices are known for working with resistance sensors, for example, a resistance thermometer, containing an amplifier connected by a terminal to a potential sensor terminal, a current transformer, the primary winding of which is connected in series with the sensor, and the secondary terminal is connected to a common terminal of resistors chord, and with the second potential sensor clamp and the reichord circuit, the current-carrying resistance of which is connected to the second input terminal of the amplifier.

In order to obtain a linear scale, the design of such devices is considerably more difficult, using as an impedance connected in series with a reohord, an additional reohord and its current-carrying resistance, with the main and auxiliary reichord sliders mechanically connected.

The proposed device is simpler than known, and its scale is linear due to the fact that it connects to the second terminal of the amplifier the beginning of the rail, and the slider through an additional resistor is connected to the common point of the secondary winding of the transformer and the potential terminal of the sensor.

Pa drawing shows a schematic diagram of the device. The device contains a resistance thermometer /, for example, platinum, current transformer 2, rheohord 3, resistors 4, 5, 6 n amplifier 7.

At the initial value of the measured temperature, the reichord slider is set at

onset of the lead, and the voltage drop on the resistance thermometer / is compensated by the voltage drop and the resistor 4. With a change in temperature, the voltage drop on the thermometer changes according to a nonlinear law. This change is compensated by the voltage between the start of the reichord and its engine. When the slider is moved, the voltage in the specified section of the rail, on the one hand, linearly depends on the engine's hollow, and on the other, on the current flowing through the reichord, which also depends on the engine's position. Therefore, the voltage removed from the reichord varies according to a non-linear law, corresponding to the law of the thermometer's resistance to temperature.

Subject invention

A compensation device for working with a resistance sensor, for example, a resistance thermometer, containing an amplifier connected by one terminal to a potential sensor terminal, a current transformer, the primary winding of which is connected in series with the sensor, and the secondary one is connected to a common terminal of resistors connected to the beginning and end of the cable, and with a second potential sensor clamp, characterized in that, in order to simplify it and reduce the methodological error from the nonlinearity of the scale when working with a sensor having a quad atichnuyu resistance dependence of the controlled parameter, it is connected to the beginning of the second slide wire clamp amplifier and the engine via a further resistor is coupled to the common point of the transformer secondary winding and a clamping potential sensor.