Compensating circuit and method for concentration and temperature drift of VOC gas sensor

Abstract

The invention discloses a compensating circuit and method for the concentration and temperature drift of a VOC gas sensor. The circuit comprises the VOC photoion sensor and an A / D converter. The VOC photoion sensor and the A / D converter are connected through a measuring bridge. The A / D converter is connected with a temperature sensor and a single-chip microcomputer. Standard gas of different concentrations is introduced into the VOC photoion gas sensor at room temperature, corresponding output voltage values are recorded, and the changing rule of the output voltage values along with the concentrations is determined; then, high and low temperature experiments are carried out, so a curve of the output voltage values along with the temperature drift is determined; the working temperature of an instrument is measured in real time through the temperature sensor, software compensation calculation is conducted on the VOC photoion gas sensor in the two dimensions including concentration and temperature through a single-chip microcomputer program, and the problem of measurement errors caused by the gas concentration and temperature drift of the VOC photoion gas sensor is solved.

Description

【Technical field】 [0001] The invention relates to the field of gas analysis, in particular to a compensation circuit and a method for concentration and temperature drift of a VOC gas sensor. 【Background technique】 [0002] VOC is the abbreviation of "Volatile Organic Compounds", that is, volatile organic compounds, such as toluene, ethylbenzene, styrene, formaldehyde, ethanol, tetradecane, TVOC, etc. [0003] VOC outdoors mainly comes from fuel combustion and transportation; indoors mainly comes from combustion products such as coal and natural gas, smoke from smoking, heating and cooking, construction and decoration materials, furniture, household appliances, cleaning agents and human body emissions. [0004] At present, many instruments on the market adjust the sensitivity and zero point of the sensor through the potentiometer, that is, the sensor itself is regarded as a linear output device, but many gas sensors are nonlinear, and the potentiometer adjustment cannot solve...

AI Technical Summary

Problems solved by technology

[0004] At present, many instruments on the market adjust the sensitivity and zero point of the sensor through the potentiometer, that is, the sensor itself is regarded as a linear output device, but many gas sensors are nonlinear, and the potentiometer adjustment cannot solve the nonlinear compensation problem of the sensor. And the potentiometer itself also has the problem of temperature drift

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