The combustible Gas Detector adopts a new generation of low power consumption and high anti-interference carrier catalytic sensor. It forms a detection bridge with two fixed resistors. When the flammable gas in the air diffuses to the surface of the detection sensor, it will rapidly burn without flame under the action of the catalyst on the surface of the sensor, and generate reaction heat to increase the resistance value of the platinum wire of the sensor, and the detection bridge will output a differential pressure signal. The magnitude of this voltage signal is proportional to the concentration of combustible gas. After it is amplified, it performs voltage and current conversion and converts the percentage content (%LEL) within the lower limit of the flammable gas explosion into a 4-20mA standard signal output.
The explosion limit data table of various combustible gases is as follows:
Measured gas | molecular formula | Relative density | Explosive limit (VOL) | Ignition temperature (°C) |
methane | CH4 | 0.55 | 5% (lower) -14.8% (upper) | 537 |
Toluene | C6H5CH3 | 3.2 | 1.1% (lower) -7.6% (upper) | 535 |
Methanol | CH3OH | 1.11 | 5.5% (lower) -38% (upper) | 385 |
Methyl formate | HCOOCH3 | 2.07 | 5% (lower) -23% (upper) | 450 |
ethyl formate | HCOOCH2CH3 | 2.65 | 2.7% (lower) -16.5% (upper) | 440 |
Methyl ether | CH3OCH3CH2 | 2.1 | 2% (lower) -10.1% (upper) | 190 |
ethane | CH3CH3 | 1.04 | 2.5% (lower) -15.5% (upper) | 515 |
Acetylene | CH=CH | 0.9 | 2.3% (lower) -100% (upper) | 305 |
ethanol | CH3CH2OH | 1.59 | 3.1% (lower) -19% (upper) | 363 |
Ethylbenzene | C6H5C2H5 | 3.66 | 1% (lower) -7.8% (upper) | 431 |
Vinyl | C2H4 | 0.97 | 2.3% (lower) -36% (upper) | 425 |
Methyl acetate | CH3COOCH3 | 2.56 | 3.2% (lower) -16% (upper) | 502 |
ethyl acetate | CH3COOCH2CH3 | 4.01 | 2.2% (lower) -11% (upper) | 460 |
N-butyl acetate | CH3COO(CH2)3CH3 | 4.01 | 1.3% (lower) -7.5% (upper) | 370 |
propane | CH3CH2CH3 | 1.56 | 1.7% (lower) -10.9% (upper) | 470 |
propanol | CH3CH2CH2OH | 2.07 | 2.2% (lower) -17.5% (upper) | 405 |
Propylene | CH2=CHCH3 | 2 | 2% (lower) -11% (upper) | 455 |
acetone | C3H6O | 2 | 2.5% (lower) -13% (upper) | 535 |
butane | C4H10 | 2.05 | 1.4% (lower) -9.3% (upper) | 372 |
butanone | C4H8O | 2.48 | 1.8% (lower) -10% (upper) | 404 |
Butadiene | CH2=CH—CH=CH2 | 1.87 | 1.4% (lower) -16.3% (upper) | 430 |
Pentane | C5H12 | 2.48 | 1.8% (lower) -10% (upper) | 404 |
Hexane | C6H14 | 2.97 | 1% (lower) -8.4% (upper) | 233 |
Heptane | C7H16 | 3.46 | 1.1% (lower) -6.7% (upper) | 215 |
Octane | C8H18 | 3.93 | 0.8% (lower) -6.5% (upper) | 206 |
nonane | C9H20 | 4.43 | 0.7% (lower) -5.6% (upper) | 205 |
carbon monoxide | CO | 0.97 | 10.9% (lower) -74% (upper) | 805 |
Ammonia | NH3 | 0.59 | 15% (lower) -33.6% (upper) | 630 |
hydrogen | H2 | 0.07 | 4% (lower) -77% (upper) | 560 |
benzene | C6H6 | 2.7 | 1.2% (lower) -8.6% (upper) | 560 |
Isobutane | C4H10 | 2 | 1.3% (lower) -9.8 (upper) | 460 |
Isopropanol | C3H8O | 2.07 | 2% (lower) -12.7% (upper) | 425 |
Cyclohexane | C6H12 | 2.9 | 1.2% (lower) -8.3% (upper) | 259 |
Cyclopentane | C5H10 | 2.4 | 1.4% (down) | 320 |
Propylene oxide | C3H6O | 2 | 1.9 (lower) -37% (upper) | 430 |
Ethylene oxide | C2H4O | 1.52 | 2.6% (lower) -100% (upper) | 435 |
diethyl ether | C4H10O | 2.55 | 1.7% (lower) -36% (upper) | 160 |
Dimethyl ether | CH3OCH3 | 1.59 | 2.7% (lower) -32% (upper) | 240 |
Xylene | C8H10 | 3.66 | 1% (lower) -7.6% (upper) | 464 |
