Questions and answers about gas detectors
Can a fixed combustible gas detector be wired in a two-wire system?
No, the two-wire signal and power supply share one wire, providing a maximum working current of 20mA, while the working current of the combustible gas sensor is 80mA, which cannot meet its normal working current.
How is the effective detection range of a fixed gas detector defined?
According to the "Monitoring of Combustible and Toxic Gases in Petrochemical Enterprises" (SH3063-1999), "The effective coverage horizontal plane radius of the 3.0.8 combustible gas detector should be 7.5m indoors and 15m outdoors. Within the effective coverage area, one detector can be installed. The distance between the toxic gas detector and the release source should not be greater than 2m outdoors and 1m indoors
What are the regulations on the installation height of fixed gas detection and alarm devices?
According to the "Design Specification for Combustible Gas and Toxic Gas Detection and Alarm in Petrochemical Enterprises" (SH3063-1999), "6.1.1 For detectors that detect combustible or toxic gases heavier than air, their installation height should be 0.3-0.6m above the ground (or floor); 6.1.2 for detectors that detect combustible or toxic gases lighter than air, their installation height should be 0.5-2m above the release source. Note: Gas with a density greater than 0.97kg/m3 (under standard conditions) is considered heavier than air; gas with a density less than 0.97kg/m3 (under standard conditions) is considered lighter than air.
What do the letters in the explosion-proof grade Exd Ⅱ CT6 represent?
Ex is an explosion-proof public symbol, d represents explosion-proof type (electrical equipment with explosion-proof shell), Class II electrical equipment for all other explosive gas environments except coal mines and underground mines, C refers to ignition energy uj, T6 refers to temperature group, T6 level is 85 degrees.
What gases can be detected by a gas detector based on PID photoionization detection principle?
Photon ion gas sensor (PID) is the most convenient and sensitive detection method for detecting organic volatile compounds (VOCs), especially for gas leaks with very low concentrations, it has unparalleled advantages over other types of sensors. In summary, PID is mainly used for the detection of VOCs, including:
Aromatic compounds: benzene, xylene, naphthalene, etc;
Saturated and unsaturated hydrocarbons: octane, ethylene, cyclohexane, etc;
Ketones, aldehydes, ethers: acetone, acetaldehyde, methyl ether, etc;
Halogenated hydrocarbons, thiohydrocarbons, alcohols, esters, hydrazine, etc.
In addition, detectable organic compounds include arsenic and ammonia.
