摘要
This paper is aimed at the actual conditions of disaster caused by gas in small and medium-sized coal mines. A new gas concentration monitoring system for coal mines is developed on the basis of gas-sensing detection and single-chip control. The monitoring system uses the tin oxide as the main material of N-type semiconductor gas sensors, be- cause it has good sensitive characteristics for the flammable and explosive gas （ such as methane, carbon monoxide）. The QM-N5-semiconductor gas sensor is adopted to detect the output values of the resistance under the different gas con- centrations. The system, designedly, takes the AT89C51 digital chip as the core of the circuit processing hardware structure to analyze and judge the input values of the resistance, and then achieve the control and alarm for going beyond the limit of gas concentration. The gas concentration monitoring system has man）, advantages including simple in struc- ture, fast response time, stable performance and low cost. Thus, it can be widely used to monitor gas concentration and provide early wamings in small and medium-sized coal mines.
基金
supported by the program of Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
the Hunan Province and Xiangtan City Natural Science Joint Foundation(No.09JJ8005)
the Industrial Cultivation Program of Scientific and Technological Achievements in Higher Educational Institutions of Hunan Province(No.10CY008)
the Technologies R & D of Hunan Province (No.2010CK3031)
