Questions about gas detectors
Can fixed combustible gas detectors be wired in a two wire system?
No, the two wire signal and power supply share the same wire, providing a high 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 "Design Specification for Combustible and Toxic Gas Detection and Alarm in Petrochemical Enterprises" (SH3063-1999), "the effective coverage horizontal radius of 3.0.8 combustible gas detectors 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
3. What are the regulations for the installation height of fixed gas detection alarm devices?
According to the "Design Specification for Combustible and Toxic Gas Detection and Alarm in Petrochemical Enterprises" (SH3063-1999), "6.1.1 Detectors for detecting combustible or toxic gases heavier than air should be installed at a height of 0.3-0.6 meters from the floor (or floor).
Note: If the gas density is greater than 0.97kg/m3 (under Standard state), it is considered as the specific air weight; Gas density less than 0.97kg/m3 (under Standard state) is considered lighter than air. 6.1.2 Detectors for detecting flammable or toxic gases that are lighter than air should be installed at a height of 0.5-2m higher than the release source
What standard gas is used for calibration of combustible gas detectors?
According to the regulations in the "Combustible Gas Detection Alarm" (JJG693-2004):
"5.1.2.1 The gas reference material shall be the same as the tested gas, and Isobutane or propane gas reference material can be used for General Instrument."
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 a platinum resistor. At a certain temperature, combustible gases catalyze combustion on its surface, causing the temperature of the platinum resistor to increase. The change in resistance is a function of the concentration of combustible gases.
6. What does F.S mean?
F. S is the acronym for full scale. It represents the size of the measurement range.
What are the current types of display screens on the market and their characteristics?
Currently, there are light-emitting diodes (LEDs), liquid crystal displays (LCDs), and organic light-emitting displays (OLEDs) on the market
What gases can the gas detector based on PID photoionization detection principle detect?
Photoionic gas sensors (PID) are a convenient and sensitive detection method for detecting organic volatile compounds (VOCs), especially for gas leaks with very low concentrations, which have unparalleled advantages compared to other types of sensors. In summary, PID sensors are mainly used for the detection of organic volatile compounds (VOCs), including:
Aromatics: benzene, xylene, naphthalene, etc;
Saturated and unsaturated hydrocarbons: octane, ethylene, cyclohexane, etc;
Ketones, aldehydes, ethers: acetone, propanal, propyl methyl ether, etc;
Halogenated hydrocarbons, thiohydrocarbons, alcohols, esters, hydrazine, etc.
In addition, detectable inorganic substances include arsenic and ammonia.
