Megfelel a a veszélyek, mi osztályoz mérgező és ártalmas gázok be kettő kategóriák: éghető gázok és mérgező gázok. Miatta a különböző tulajdonságaik és veszélyeik, kimutatásuk módszereik szintûségñváltozó.
This should be taken very seriously when calibrating the instrument. For the sake of , we should generally issue an alarm when the combustible gas concentration is 10% and 20% of LEL, where 10% LEL is referred to. Make a warning alert, and 20% LEL is called a danger alert. That is why we refer to combustible gas detectors as LEL detectors.
It should be noted that, The 100% displayed on the LEL detector is not that the concentration of combustible gas reaches 100% of the gas volume, but that it reaches 100% of the LEL, which is equivalent to the lower explosive limit of combustible gas. If it is methane, 100% LEL=4% volume concentration (VOL). In operation, the detector that measures these gases in an LEL manner is a common catalytic combustion detector. Its principle is a dual bridge (commonly referred to as a Wheatstone bridge) detection unit. One of these platinum wire bridges is coated with catalytic combustion substances. Regardless of the flammable gas, as long as it can be ignited by the electrode, the resistance of the platinum wire bridge will change due to temperature changes. This resistance change is proportional to the concentration of the flammable gas. The concentration of the flammable gas can be calculated through the instrument's circuit system and microprocessor. A thermal conductivity VOL detector that directly measures the volume concentration of combustible gases can also be obtained on the market, and there are already detectors that combine LEL/VOL. VOL combustible detectors are particularly suitable for measuring combustibles in oxygen deficient environments
