RU15026U1 - DEVICE FOR MEASURING TOXIC GAS CONCENTRATION IN AIR - Google Patents

Abstract

A device for measuring the concentration of toxic gases in the air, containing a power source, a measuring bridge circuit, a catalytic sensing element is integrated in one shoulder, and a compensation element, an operational amplifier, a control unit in the other, characterized in that a single-chip micro is used as the control unit - A computer with read-only memory connected to the outputs of the analog-to-digital converter and controlling the heating of the sensitive and compensation elements via a digital Tax converter whose output is connected to a measuring bridge circuit.

Description

DEVICE FOR MEASURING TOICIC COICEITRATION

GAS IN THE AIR

The solution relates to the field of analytical instrumentation and can be used to measure the content of toxic gases in the air while controlling the atmosphere of industrial premises in the chemical, gas and coal industries.

A device is known that contains a mixing and measuring chamber, a bridge measuring circuit connected to a power source, a catalytic sensing element is included on one shoulder, and a Vanya Ya instrument is recorded in the diagonal. Gas and liquid analyzers. Per. Sc.- M: Energy, 1970 .-- S. 162-163.

The disadvantage of this device is the lack of a device control unit, low measurement accuracy and manual maintenance.

Closest to the claimed one is a device consisting of a power supply, a bridge measuring circuit, in one arm of which a catalytic sensing element is included, and in the other - a compensating element, of a differential amplifier, a reading unit and a control unit including a clock frequency generator, two decimal counters, trigger, two 2I-NOT elements and two inverters According to the program of the control unit 1, the read unit implements a time-selective measurement procedure that automatically eliminates drift 2000105839

G 01N 27/14

for A.S. USSR, No. 1627960 G N 27/16, publ. 02/15/91. The disadvantage of this device is the significant out-of-pocket costs due to the complexity of constructing the control unit.

The objective of the proposed solution is to improve the design of the device for measuring the concentration of toxic gases in the air.

The technical result from the use of a utility model is to simplify the device and reduce the number of its structural elements.

The technical result is achieved in that in a device for measuring the concentration of toxic gases in air containing a power source, a measuring bridge circuit, in one arm of which a catalytic sensing element is integrated, and in the other a compensation element, an operational amplifier, a control unit, as a control unit a single-chip microcomputer with a constant memory device is used, connected to the outputs of the analog-to-digital converter and controlling the heating of the sensitive and compensation elements through the digital-to-analog ggreobrazovatel whose output is connected to a measuring bridge circuit.

The drawing shows a structural diagram of a device.

The device contains a power source 1, a bridging measuring circuit 2, in one arm of which a catalytic component is included, and in the other a compensation element, an operational amplifier

3, analog-to-digital converter (ADC) 4, a control unit based on a single-chip microcomputer 5, which controls the detection process using a program recorded in its read-only memory, digital-to-analog converter (DAC) 6.

A device for measuring the concentration of toxic gases works as follows. When the supply voltage is supplied from the power source 1, the microcomputer 5 is automatically started, after which it starts work according to the program recorded in the internal read-only memory (ROM) of the microcomputer 5. Under the control of the program, the sensitive and compensation elements are heated by supplying the corresponding value signal to the input of NAL 6, the output of which is connected to the bridge measuring circuit 2, and automatic balancing of the bridge. The air mixture containing the detected gas, falling on the surface of the catalytic sensor, causes a change in the resistance of the platinum film of the catalytic sensor, proportional to the concentration of gas in the controlled medium. The imbalance signal of the measuring bridge 2 is amplified by an operational amplifier 3 and fed to the input of the ADC 4, which after conversion transmits it to the microcomputer 5 for processing and indication.

3 Thus, the proposed device for measuring concentration

toxic gases in comparison with the prototype can significantly reduce hardware costs due to the use of a single-chip microcomputer instead of a complex control unit and a reading unit, which leads to a decrease in its overall dimensions and increased reliability of the device.

H

Claims (1)

A device for measuring the concentration of toxic gases in the air, containing a power source, a measuring bridge circuit, a catalytic sensing element is integrated in one arm, and a compensation element, an operational amplifier, a control unit in the other, characterized in that a single-chip micro is used as the control unit - A computer with read-only memory connected to the outputs of the analog-to-digital converter and controlling the heating of the sensitive and compensation elements via a digital Tax converter whose output is connected to a measuring bridge circuit.