Combustible gas detector consists of two parts, test and detection.
Combustible gas detector testing part is the principle of the instrument sensor is detecting element and fixed resistance and zero potentiometer testing bridge road. Bridge circuit with platinum wire as the carrier catalytic element, after electrify platinum temperature up to working temperature, air spreads in a natural way or other way to reach the surface of the element. When no combustible gas in the air, bridge circuit output is zero, when the air contains flammable gases and spread onto the detecting element, because the flameless combustion catalyst, temperature, detection element, platinum resistance increases, the bridge road out of balance, to have a voltage signal output, the size of the voltage is proportional to the concentration of combustible gas, signal amplifying, modulus conversion, through liquid display shows the concentration of combustible gas. The principle of detecting part is when the concentration of combustible gas being measured exceeds limit, after amplification of bridge circuit output voltage and set the voltage detection circuit, through the voltage comparator, square wave generator output a square wave signals, sound control, light detection circuit, buzzer sound continuously, light-emitting diodes, signal detection.Can be seen from the principle of combustible gas detector if an electromagnetic interference will affect detection signal, data deviation;If there is a collision, vibration causing circuit will now detect equipment failure;If too humid environment or equipment into the water, but also may cause of combustible gas detector in short circuit, or line resistance value changes, fault detection.
Combustible gas is a state of fuel quality, refers to with the concentration of the air (oxygen) or in a certain range form premixed gas mixing, meet the fire explode, energy release a large amount of gas in the combustion process.Many combustible gases, such as hydrogen (H2), carbon monoxide (CO), methane (CH4), ethane (C2H6) (C3H8), propane, butane (C4H10), ethylene (C2H4), propylene (C3H6), butene (C4H8), acetylene (C2H2), propiolic (C3H4), butyl acetylene (C4H6), hydrogen sulfide (H2S), phosphine (PH3), etc.
Combustible gas detector is installed in industrial and civil architecture is used for single or multiple response of combustible gas concentration detector.Daily use most of the combustible gas detector is catalytic type combustible gas detector and semiconductor type combustible gas detector two types.Hotel, the guesthouse, the family between making use of coal gas, natural gas, liquefied petroleum gas mainly use semiconductor type combustible gas detector, industrial sites of flammable gas, flammable vapor mainly use type catalytic combustible gas detector.