Optimization of the methane gas sensor immunity based on electromagnetic measurement

In order to clear up false alarms caused by electromagnetic interference, a novel field way was put forward in which the radiated emission measurement in the coal mining roadway was finished. The data was obtained through the spectrum analyzer. Firstly, the optimization of explosion-proof enclosure was completed according to the distribution of radiated interference characteristics. As a result, with the optimization of explosion-proof enclosure, the false alarms of methane gas sensor significantly reduced; however, there were still occasionally false alarms when nearby electrical equipments were switched on and off. The false alarms were caused by conducted interference mostly from lines. Secondly, the complex EMI filter was put forward at power ports and the EMI was controlled within the allowable range. In the end, the running results demonstrated that the problem of false alarms had been resolved successfully. It is concluded that the improved measures are highly remarkable in enhancing the immunity of the methane gas sensor.