Something About Gas Detectors
1. Can the fixed combustible gas detector be made into two-wire wiring?
No, the two-wire signal and power supply share one wire, and the maximum working current provided is 20ma, while the working current of the combustible gas sensor is 80ma, which cannot meet its normal working current.
2. How is the effective detection range of a fixed gas detector defined?
According to the "Code for Design of Combustible Gas and Toxic Gas Detection and Alarm in Petrochemical Enterprises" (SH3063-1999):
"3.0.8 The effective coverage horizontal plane radius of the combustible gas detector should be 7.5m indoors and 15m outdoors. One detector can be installed within the effective coverage area. The distance between the toxic gas detector and the release source, It should not be larger than 2m outdoors, and not larger than 1m indoors."
3. What are the regulations on the installation height of the fixed gas detection alarm?
According to the "Code for Design of Combustible Gas and Toxic Gas Detection and Alarm in Petrochemical Enterprises" (SH3063-1999):
"6.1.1 The detectors for detecting combustible gases or toxic gases heavier than air should be installed at a height of 0.3-0.6m from the floor (or floor).
Note: Gas density greater than 0.97kg/m3 (under standard conditions) is considered heavier than air; gas density less than 0.97kg/m3 (under standard conditions) is considered lighter than air.
6.1.2 The detector for detecting flammable gas or toxic gas lighter than air should be installed at a height of 0.5-2m higher than the release source. "
4. What kind of standard gas is used to calibrate the combustible gas detector?
According to the "combustible gas detection and alarm" (JJG693-2004):
"5.1.2.1 Gas standard substance Use the same standard substance as the gas to be measured, and isobutane or propane gas standard substance can be used for general-purpose instruments."
The company uses isobutane for calibration.
5. What is the principle of catalytic combustion detection?
The principle of catalytic combustion is to prepare a high-temperature-resistant catalyst layer on the surface of the platinum resistor. At a certain temperature, the combustible gas is catalytically combusted on its surface. The combustion causes the temperature of the platinum resistor to rise and the resistance to change. The change value is the concentration of the combustible gas. function.
6. What does F.S mean?
F.S is an acronym for full scale. It indicates the size of the measurement range.
7. What kinds of display screens are currently on the market, and what are their characteristics?
Light-emitting diodes (LEDs), liquid crystal displays (LCDs), and organic light-emitting displays (OLEDs) are currently on the market.
8. Which gases can be detected by the gas detector based on the principle of PID photoionization detection?
Photoion gas sensor (PID) is the most convenient and sensitive detection method for detecting volatile organic compounds (VOCs), especially for gas leakage with very low concentration, which has incomparable advantages over other types of sensors. Generally speaking, photoion gas sensor The sensor (PID) is mainly used for the detection of volatile organic compounds (VOCs), which include:
Aromatics: benzene, xylene, naphthalene, etc.;
Saturated and unsaturated hydrocarbons: octane, ethylene, cyclohexane, etc.;
Ketones, aldehydes, ethers: acetone, propionaldehyde, propylmethyl ether, etc.;
Halogenated hydrocarbons, thiohydrocarbons, alcohols, esters, hydrazines, etc.
In addition, detectable inorganic substances include: arsenic, ammonia.
