SU1649584A1 - Multichennal meter - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure temperature and other physical quantities using resistive sensors. The invention aims to improve measurement accuracy and simplify the device. The device contains a power source 1, a voltage meter 2, a pulse shaper 3, a trigger 4, a multiplexer biv each measuring channel, the first and second keys 6 and 7, the sensor standard 8 and the temperature sensor 9, as well as output 10, control input 11 and address inputs 12 devices. 1 il.

Description

The invention relates to a measurement technique and can be used to measure temperature and other physical quantities using resistive sensors, as well as to automatically monitor the state of systems of autonomous objects.

The purpose of the invention is to improve the measurement accuracy and simplify the device.

The drawing shows the functional diagram of the device.

The device contains a power source 1, a voltage meter 2, a pulse shaper 3, a trigger 4, a multiplexer 5 and in each measuring channel the first and second keys 6 and 7, the reference sensor 8 and the temperature sensor 9, the output, the control input and the address inputs of the device respectively 10. 11 and 12.

The device works as follows.

A strobe pulse triggers a pulse generator 3 that generates single pulses. At the same time, the digital code received at the address 12 inputs of the device selects the analog input of the multiplexer 5. corresponding to the number of the measured channel. The measurement process in the channels is the same and consists of 2 cycles: in the first cycle, a single pulse emitted by the pulse shaper 6 changes the state of the trigger 4, while in the selected channel the key 6 opens, the key 7 closes. As a result, a voltage is generated at the output of the voltage meter 2:

u1 (Yae + P + G2) 1et,

where R-J is the resistance of the reference sensor;

ri, r2 - resistances of the sensor connecting wires;

1et - the current value of the reference sensor.

In the second cycle, by the next pulse emitted by the pulse shaper 3, the state of the flip-flop 4 is reversed, and the key 6 is closed, the key 7 is opened. As a result, a voltage is generated at the output of the meter 2

w

Yo

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ate

00 Ј

Uz - (Rr + P + G2) IT, where RT is the resistance of the thermal sensor,

IT is the current value of the sensor.

The result of the measurement is the voltage difference.

AU-U2-Ui-RTlT-R8Tl3T.

Similarly, measurements are carried out in the remaining channels.

Thus, the device provides the possibility of high-precision measurement due to the absence of the dependence of the measured voltage drop on the sensor on the resistance of the connecting wires. An increase in measurement accuracy is achieved by the fact that L U is measured with respect to a highly accurate zero count due to the use of RST RT, for example, with elements of the same physical properties and thereby taking into account varying operating factors and physical properties of the sensitive elements themselves.

Claims (1)

Invention Formula A multichannel measuring device containing a power source, a voltage meter, the output of which is the output of the device, a pulse shaper, the input of which is the control input of the device, in each measuring channel the first and second keys, the thermal sensor, the first output of which connected to the first input of the second key, the second terminals of the temperature sensors of each measuring channel, the first output of the power source are combined and connected to the first input of the voltage meter, which is due to the fact that, in order to improve the accuracy of measurement and simplification, a trigger is inserted into it, a multiplexer and in each measuring channel-sensor — a standard, a control input and the address inputs of a multiplexer are the control input and address inputs of the device, respectively, the multiplexer output and the second output of the power source dinene and connected to the second input of the voltage meter, the output of the pulse driver is connected to the trigger input, in each measuring channel the first output of the reference sensor is connected to the first input of the first switch, the second outputs of the sensor reference of each measuring channel are combined and connected to the first input of the measuring device the outputs of the first and second keys of the corresponding measuring channel are combined and connected to the corresponding information input of the multiplexer; the direct and inverse outputs are connected to torym inputs of the first and second keys each izmeritelnogaka- Nala, respectively.