SU1732187A1 - Device for measuring temperature - Google Patents

Abstract

The invention relates to a technique for measuring temperatures and is intended to measure mainly low temperatures. The aim of the invention is to increase the sensitivity of the device. The device contains a transistor 1, resistors 2, 7, contacts of an electromechanical relay (EMR) 3, 6, 8, a pulse generator 4, an inductor 5, a capacitor 9, a repeater 10, a processing unit 11, a power source 12, an EMR winding 13, a start contact 14, amplifier 15, recorder 16, frequency meter 17, arithmetic logic unit 18, correction unit 19. 1 il. i (L C b: about to 00 1

Description

The invention relates to a technique for measuring temperatures and is intended to measure mainly low temperatures.

A temperature sensor is known in which a transistor is used as a sensitive element, the p – n junction characteristic of the p-junction is a function of temperature, the transistor being connected to the negative feedback circuit of the operational amplifier “

The disadvantage of the sensor is a narrow range of measured temperatures.

The closest to the proposed device is a quartz thermometer, comprising a generator with a temperature-sensitive quartz resonator, a reference generator, a mixer, a coincidence circuit, a frequency meter and a digital display unit,

i

The disadvantage of this device

is that the heat-sensitive quartz resonator, placed in a sealed ampoule, has a high inertia and low relative sensitivity

The purpose of the invention is to increase the sensitivity of a device for measuring temperature.

The goal is achieved by introducing an electromechanical relay, a repeater, a first and second resistors, an inductor, a capacitor, a transistor, the base of which is connected to a common point through the first resistor into a temperature measuring device containing a pulse generator, a processing unit, a power source. to the emitter, and through the first normally open contact of the electromechanical relay - to the output of the pulse generator, the collector of the transistor is connected via a repeater to the processing unit, and through the second resistor connected thereto in parallel across the normally open contact of the electromechanical relay is connected to the capacitor inductance katuag- ke, which is included in parallel normally closed contact of the electromechanical relay in series with the inductor includes a power supply, the contact start, the winding of the electromechanical relay.

The drawing shows a block diagram of the device

The device contains a transistor 1, a resistor 2, a normally open contact 3 of an electromechanical relay (EMR), a generator of 4 pulses, an inductor 5, a normally closed contact 6 EMR, a resistor 7, normally closed contact 6 EMR, a resistor 7, normally closed contact 8 EMR, capacitor 9, repeater 10, processing unit 11, power supply 12, winding 13 EMR, contact, Start 14, amplifier 15, recorder 16, frequency meter 17, arithmetic logic unit (ALU) 18, correction unit 19

five

The device works as follows

To start the device, to the power source 12 by means of the Start 14 contact, winding 13 EMR is connected. At the same time, contacts 6 and 8 are opened, disconnect the capacitor from the circuit and turn on the inductor coil 5 into the collector circuit of the temperature sensor, and through contacts 3, which are closed, the base is connected to the generator 4 of pulses, from which the unlocking the pulses, with the help of which the transistor temperature sensor is brought to the working 5 state (at zero potential on the base, a potential of 4-12 V is established on the collector)

0 After disconnecting the winding 13 of the relay from the power source 12, the pair of contacts 3 opens and disconnects 0 the point of the transistor 1 from the generator 4 pulses-1 F ow, the pair of contacts b closes

5 and short-circuits the inductance coil 5 which, however, does not take part in the further operation of the device. When a pair of normally closed contacts 8 is closed, the capacitor 9

0 is connected in parallel to the resistor 7, after which a sawtooth voltage begins to form on the collector of the transistor temperature sensor, the frequency of which is

5 is the temperature; and increases with increasing temperature ... The sawtooth pulses from the output of the repeater 10 are fed to the amplifier 15, from the output of which the pulses

A predetermined amplitude and duration are fed to the counting input of the frequency meter 17. From the output of the frequency meter 17, the digital code goes to the first information inputs of the ALU 18, in which the operation is performed to subtract the number recorded in the correction unit 19 from the number on the output of the frequency meter 17.

With the help of correction block 19, an arbitrary point of reference can be set, which, for example, is necessary when determining the temperature increment in the calorimeter. „

Claims (1)

As a temperature sensor, unpackaged transistors can be used, the volume of which does not exceed 1 mm9, due to which its inertia will be comparable to the inertia of thermoelectric converters. Invention Formula Temperature measuring device comprising a pulse generator Processing unit, power supply, characterized in that, in order to increase sensitivity, an electromechanical relay, a repeater, a first and a second resistors, an inductor, a capacitor, a transistor, the base of which is connected to the common point and emitter through the first resistor, are introduced into it and through the first normally open contacts of the electromechanical, the relay to the output of the pulse generator, the collector of the transistor is connected via a repeater to the processing unit, and through a second resistor with a parallel connected, to it through a norm cial open contact electromechanical relay Capacitors - inductor, parallel to which is included the normally closed contact of the electromechanical relay in series with an inductor incorporated power source con- tact 5 Start .obmotka electromechanical relay of five 0