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Coal Mine Safety Monitoring System Based on ZigBee

A methane monitoring system, consisting of methane sensor nodes and controllers with ZigBee networks between them, has been investigated for coal mine safety. The nodes were in comparatively flexible position. While not working, the nodes were put into hibernation so as to low consumption. While working, the sensor KGS-20 detected methane and sent voltage to CC2430 to carry on A/D conversion. After data processing by CC2430, the node would alarm and display and transmit data to its controller. The controller transmitted data to monitoring station by CAN bus. In experiment a sensor node was put in methane with eight different concentrations and the results were shown in LCD. The results show that all errors are all less than 0.05% and its average error is 0.023%. The errors are accordance with the rules for error range in coal mine.