1. The explosion limit, the upper limit and lower explosive limit
Because of the combustible gas (vapor) with a mixture of air and is not in any concentrations in fire explosion, must be in a certain concentration range of fire to explode.
This encounter can fire explosion of combustible gas concentration range, says the combustible gas explosion limit (including the explosion limit and the lower explosive limit)
Lower explosive limit: the combustible gas in the air in the flame spread or the lowest concentration of the explosion, represented by % LEL
Combustible gas explosion limit: in the air physical fitness to the highest concentration of flame spread or explosion, with % of education-the said
2. Combustible gas, toxic gas
Flammable gas, flammable gas was very broad, such as: city gas, liquefied petroleum gas, industrial raw material gas, ethylene, propane, methane, kerosene, toluene, formaldehyde, etc.
When the lower explosive limit is less than 10% of the gas explosion limit and the lower explosive limit in more than 20% of the difference between the gas, is defined as a flammable gas.
Poisonous gas: in the process of industrial production using goods produce harmful to human body and can cause acute or chronic poisoning the gas or vapor, referred to as a toxic gas, its value (allowable concentration) in 200 parts per million as a harmful gas, usually used PPM, said one million of the total volume of the gas, the gas volume fraction of the a, expressed in one over one million.
Some gas is a combustible gas, also toxic gas
Percent concentration and PPM the relationship between the two kinds of concentration
% = 6 PPM / 1 PPM = 10-10000% (one over one million)
Here following are our fixed gas detectors
Basic parameters:
Size:144 mm * 190 mm * 74 mm
Weight: about 1130 g
Sensor types: catalytic combustion type,
Destination gas: EX
Response time: ≤20s(EX)
Working pattern: continuous work
Working voltage: DC24V
Output signal: 4-20 mA
Output way: two wire or three wire, three wire system can output a set of relay switch signal
Temperature range: - 20 ℃ ~ 50 ℃
Humidity: 15% ~ 90% RH (No condensation)
Explosion-proof number: CE101084
Explosion-proof marks: Exd II CT6
Connection mode: three-wire system according to the instruction manual one-to-one connection, two wire circuit done meter processing.
Transmission cables: two core shielded cable, section 2 x 1.5 mm2
(three-wire system adopts three core shielded cable 3 x 1.5 mm2)
Contact:dianna@huafankj.com