Development Of Mine Gas Sensor And Alarm Automatic Calibrator System

As the key component of coal mine safety monitoring system, the mine gas sensors and alarming device is the front end of the detecting element in the coal mine safety monitoring system. It can detect the concentration of all kinds of poisonous and harmful gas under the mine on real time. Its stability and reliability has very important significance for the whole monitoring; system to determine whether the concentration is overrunning.The current domestic gas sensors and alarming device mostly use gas sensitive element as the core component. It is based on the heat catalytic principle. After used a period, it will produce the phenomenon such as zero drift and span drift to such instruments. The case that poisonous and harmful gas concentration is over the red line but the alarm sensors and alarming device do not work will happen if the adjustment is not timely. Therefore in order to ensure the production line operating reliably and stably, the monitoring equipment need a regular adjustment on the parameter calibration. It is required in 《Coal Mine Safety Monitoring System and Code for Testing Instrument Use》 that perfect mine monitoring system must be constructed and the sensor and the alarming device monitoring devices such as the need for debugging, calibration, regularly to ensure performance in good condition. It is regulated in 《Coal Mine Safety Regulations》 that use the carrier catalytic element testing equipment, such as methane sensor and portable methane detection alarming device, etc. to adjust the standard gas sample and air sample set-up every7days. There are many coal mines in our country, and various types of gas sensors and alarming device are used. The task of adjustment is very heavy. Mine gas sensors and alarming device of automatic calibration system has the advantages to increase the speed, save the human labor, and reduce the maintenance cost. It has important practical significance and high practical value for the coal mine production safety.From the demand of coal mine safety rules and the reality of the market demand, this paper expounds the necessity of designing automatic calibration system. It analyzed several important principles in the automatic calibration system. The signal acquisition circuit principle can realize real-time sensor output signal acquisition, the image signal sampling principle can realize real-time alarming device density, and the infrared calibration principle can realize automatic closed loop sensor calibration.Based on C8051F020MCU, the hardware circuit was set, and the smallest system design, power design, image design, signal collection circuit signal collection design, the gas control design and control design of road segments were completed. The system implementation process was introduced in the software part. The PC interfaces were designed, and the design process was expounded. Experiments have been carried out to verify the system, the rationality of system design and function of the advanced nature were analyzed through the comparison of data.The system has been applied to practical production. Judging from the feedback of each manufacturer, this system has good stability, strong anti-jamming, detection and high precision. It can significantly increase calibration and verification efficiency of the sensor and alarm device, so it can provide an important guarantee for the efficient production of coal mines.