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### Gas Alarm FAQ

Posted: Thu Feb 11, 2021 9:01 am
1. The meaning of %LEL concentration in the measurement range of gas alarm
%LEL refers to the lower limit of explosion. The lowest concentration of combustible gas that will explode when it encounters an open fire in a confined space. In the case of methane, the lower limit of explosion European standard: 100%LEL=4.4% VOL 1% LEL=440PPm.

2. The meaning of gas alarm measurement unit vol% concentration
VOL % is the volume percentage concentration, VOL is the volume ratio, is the volume ratio of non-flammable gas.
That is, the unit volume is divided into 100 parts, including 1 part of gas, whose concentration value is 1vol%. Therefore, the concentration of gas is commonly detected. For example, when the gas concentration is 100vol% in replacement, it indicates that the pipeline is pure gas, and we get that 1vol%=10000PPm

3. The meaning of measuring PPM concentration
It means a concentration of one part per million, which is divided into a million parts per unit volume. One part of the gas is 1PPm. Therefore, PPm is a very low concentration, which is used to measure whether there is a gas leak.
1PPm= 1/millionth concentration =1cm³in1m³, 1vol%=10000PPm

4. How is the pressure of gas pipeline converted
1Mpa=1000Kpa=1000000pa=10 kg, the general low pressure pipeline between 2000pa-3000pa.