Mining Carbon Monoxide Transmitter

With the rapid development of the mining enterprises, mine safety inproduction accidents occur more frequently. Combustible and toxic gases underthe mine are the major factors which induced accidents and carbon monoxide isone of the dangerous gases must be real-time monitoring. Therefore fast andaccurate detection of carbon monoxide under mine is particularly important. Thethesis of carbon monoxide transmitter can achieve carbon monoxide fast, high-stability detection, thus ensuring the safety of underground workers.This thesis based on the ME3-CO electrochemical sensor, under the controlof the microcontroller and adopted precision measuring amplifier circuit, displaycircuit, alarm circuit, digital temperature compensation circuit, infrared remotecontrol module and frequency output circuit etc. to achieve the gas concentrationof carbon monoxide monitoring and display in the operating environment for coalmine. Electrochemical sensor output the weak current signal, and the weakcurrent signal via low offset and low drift precision amplifier circuit, thenconverted into a voltage signal, and sent to the ADC module of microcontrollerto convert into a corresponding, then the digital signal is converted to aconcentration signal by single chip microcomputer for data processing. Theoutput current signal of electrochemical sensor is affected vulnerably by ambienttemperature. By analyzing to determine the relationship between electrochemicalsensor sensitivity and temperature, this paper presents the measuring temperaturecircuit about temperature sensor18B20and compensation algorithm realizedtemperature compensation, environmental temperature effect on precision oftransmitter control. For convenience, reliability considerations, the thesis adoptedan infrared remote control module for alarm value setting and calibration of zeroand sensitivity. Alarm circuit is used for sending out sound and light alarm signalwhile the carbon monoxide concentrations exceed the set alarm threshold.Display module is used for displaying the carbon monoxide concentration in real time. The infrared remote control module set the alarm threshold value, thestandard gas concentrations and storing the calibration in the calibration process.This paper achieved ultimately a fast and high stability detection of the carbonmonoxide gas and has significance to improve safety production level of coalmine and safety production management efficiency.