General instrumentation in the normal operation or accident may spark, arc, hot surfaces and hot particles, and have some energy, as ignited explosive gas mixture of flammable gas source of fire. Most safety instrumentation such as natural gas alarms and carbon monoxide alarms are explosion-proof, with the aim of preventing the instrument from exploding itself. In order to prevent the gas alarm need to take what specific measures?
Gas alarm explosion-proof mainly the following measures:
1, in the scope of explosion-proof, the sensor may not have mechanical electrical contacts to prevent electrical contact sparks.
2, the sensor power supply current must be less than the specified level (usually mA).
3, all-metal shell structure, providing the overall shell grounding terminal, to avoid electrostatic discharge.
4, the sensor has a gas-permeable structure, no gas accumulation space.