Composition of Fixed Gas Detectors
The fixed gas detector consists of an alarm controller and a detector. The controller can be placed in the duty room and mainly controls various monitoring points. The gas detector is installed in the location where gas is most prone to leakage. Its core component is the built-in gas sensor, which detects the concentration of gas in the air.
The detector converts the gas concentration detected by the sensor into an electrical signal, which is transmitted to the controller through a cable. The higher the gas concentration, the stronger the electrical signal. When the gas concentration reaches or exceeds the alarm point set by the alarm controller, the gas alarm sends an alarm signal and can activate external devices such as solenoid valves and exhaust fans to automatically eliminate hidden dangers.
1. Transmission distance of cables
The maximum distance is 1000 meters, which is related to the number of gas detectors and the thickness of the cables used. The source distance can be increased by adding signal amplifiers to increase the transmission distance.
What are the output signals of the detector
Three wire system: 4-20mA standard signal, two-wire system: M-BUS signal or RS485 signal, four wire system: RS485 signal, standard RS485 signal
3. Common cable specifications
Three wire distribution system: Generally, national or non-standard RVV3 * 1.0-1.5-2.5mm2 is used. If there is signal interference, national or non-standard RVV3 * 1.0-1.5-2.5mm2 should be used (letter R represents flexible wire, letter V represents semi insulating polyvinyl chloride (PVC), letter P represents shielding).
Four wire bus: generally using national or non-standard RVV4 * 1.0-1.5-2.5mm2. If there is signal interference, the national or non-standard RVV4 * 1.0-1.5-2.5mm2 should be used (letter R represents flexible wire, letter V represents semi insulating polyvinyl chloride (PVC), letter P represents shielding).
Two wire bus: using RVS2 * 2.5 twisted pair (letter S represents twisted pair, letter R represents flexible wire, letter V represents polyvinyl chloride (insulator))
