SU433359A1 - DIGITAL DEVICE FOR TEMPERATURE DIFFERENCE MEASUREMENT - Google Patents

Description

one

And - “) is non-existent with 11: one-piece technique.

A device for measuring the temperature difference is known, which contains differential thermocouples with foxes, where a part of thermoelectric power is used as the commanding parameter. D. s., obtained from the divider from the thermocouple measuring the greater of the temperature.

However, when the temperature difference decreases, the error increases dramatically due to the incompatibility of the compensation voltage with the difference in thermoelectric power. d.

The proposed device does not have this disadvantage and differs from the known fact in that additional resistors in it are connected to a switch controlled by a relay, the winding of which is connected in series with a reohord and a resistor fed by an oppositely connected voltage to e. d. corresponding thermocouple.

The drawing shows a diagram of the proposed digital device.

Termopar 1, measuring a high temperature, is included in the measuring circuit through a voltage divider consisting of an additional DC resistor

R, relay, resistor, powered from the power source 2 through the resistor Ld.

Thermocouple 3 out. Measures lower temperature. The measuring device consists of the resistors R that make up the shoulders of the bridge, fed from source 4, measuring resistors shunted by resistors or depending on the position of the switch P. The switch is set to position I or II automatically depending on the range of absolute values of temperature using a relay the current in the winding of which depends on the temperature measured by the thermocouple 1. To obtain a digital output, the circuit includes a digital millivoltmeter 5 with an additional rheo chord. m / fed from the stabilizers This source is 6 through a resistor. With an appropriate choice of elements, the voltage and voltage taken from the reshords and R / t change in proportion to the output voltage.

0 scheme and has a linear dependence on the temperature difference.

Subject and requirement A digital device for measuring the temperature difference, containing a bridge potentiometric circuit with additional 5 resistors, one of the diagonals of which has a stabilized power source and the other with counter-activated thermons. , and an additional circuit consisting of a source of stabilized power, a resistor and a rheochord, the engine of which is connected to the measuring rheochord engine, characterized in that

measurement accuracy, in it additional resistors are connected to a switch controlled (a relay, the winding of which is connected nosledovalelno with a reohord and a resistor fed by a switched-on voltage with respect to the emf of the corresponding thermocouple.

/