Improving electromagnetic compatibility of gas sensor based on electromagnetic measurement

In order to eliminate false alarms, issued by gas sensors in coal mining,caused by Electromagnetic Interference (EMI), a novel field way was brought forward in which the radiated emission measurement in the coal mining roadway was accomplished. The data was acquired through the R&S spectrum analyzer FSP7. With analyzing the influence of alarm and ventilation apertures on enclosure shielding properties, the optimization of explosion-proof enclosure was finished according to the distribution of radiated interference characteristics. As a result, with the optimization of explosion-proof enclosure, the false alarms of 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. Therefore the complex EMI filter was put forward at power ports and the EMI was controlled within the allowable range. The running results demonstrated that the problem of false alarms had been resolved successfully. It is concluded that the improved shielding and filtering are highly significant in enhancing the Electromagnetic Compatibility (EMC) of the gas sensor.