Operating and Maintaining Combustible Gas Detectors
1, combustible gas detector is industrial and civil buildings installed in the use of single or multiple combustible gas concentration response detector. Daily use * more combustible gas detector is catalytic combustible gas detector and semiconductor combustible gas detector two types. Restaurants, hotels, home production room using gas, natural gas, liquefied petroleum gas places mainly use semiconductor-type combustible gas detector, the distribution of combustible gases, combustible vapours of industrial premises mainly use catalytic combustible gas detector.
2, catalytic combustible gas detector is the use of refractory metal platinum wire heated resistance changes to determine the concentration of combustible gases. When the combustible gas into the detector, in the platinum wire surface oxidation reaction (flameless combustion), the heat generated by the platinum wire temperature, and the platinum wire resistivity changes, so when encountered at high temperatures and other factors when the temperature of the platinum wire changes, and the platinum wire resistivity changes, the detection of the data will also change.
3,Semiconductor combustible gas detector is the use of semiconductor surface resistance changes to determine the concentration of combustible gases. Semiconductor combustible gas detector with high sensitivity gas-sensitive semiconductor components, it is in the working state, encountered combustible gases, the semiconductor resistance drops, the drop in value and the concentration of combustible gases have a corresponding relationship.
4,Combustible gas detector consists of two parts, detection and detection, with detection and detection functions. Combustible gas detector detection part of the principle is the instrument's sensor using detection elements and fixed resistance and zeroing potentiometer constitutes a detection bridge. Bridge to the platinum wire as a carrier catalytic element, the platinum wire temperature rises to the operating temperature after power, the air to natural diffusion or other ways to reach the surface of the element. When there is no combustible gas in the air, the output of the bridge is zero, when the air contains combustible gases and diffuse to the detection element, due to the catalytic effect of flameless combustion, so that the temperature of the detection element rises, the platinum wire resistance increases, so that the bridge is out of balance, so that there is a voltage signal output, the size of this voltage and the concentration of combustible gases is directly proportional to the signal amplified, the analogue-to-digital conversion, through the liquid display to show the The signal is amplified and converted to analogue-digital, and the flammable gas concentration is displayed through the liquid display. Detection part of the principle is when the measured flammable gas concentration exceeds the limit value, after amplification of the bridge output voltage and circuit detection of the set voltage, through the voltage comparator, square wave generator outputs a set of square wave signals to control the sound, light detection circuit, the buzzer occurs in a continuous sound, light-emitting diode flashes, issued by the detection signal. From the principle of combustible gas detector can be seen if there is electromagnetic interference will affect the detection of the signal, data bias; if there is a collision, vibration and thus cause the equipment will now detect the failure of the circuit; if the environment is too humid or equipment into the water, it may also cause the combustible gas detector short circuit, or line resistance value changes, detection failure.
