The combustible gas detector consists of two parts: detection and detection, with detection and detection functions.
1. Detection part
The principle of the detection part of the combustible gas detector is that the sensor of the instrument uses a detection element, a fixed resistance and a zero-adjusting potentiometer to form a detection bridge. The bridge uses platinum wire as the carrier catalytic element. After electrification, the temperature of the platinum wire rises to the working temperature, and the air reaches the surface of the element by natural diffusion or other methods. When there is no flammable gas in the air, the output of the bridge circuit is zero. When the flammable gas in the air diffuses to the detection element, flameless combustion occurs due to the catalytic action, which increases the temperature of the detection element and increases the resistance of the platinum wire. , so that the bridge circuit is out of balance, so that there is a voltage signal output, the magnitude of this voltage is proportional to the concentration of flammable gas, the signal is amplified, analog-to-digital conversion, and the concentration of flammable gas is displayed through the liquid display.
2. Detection part
The principle of the detection part is that when the measured flammable gas concentration exceeds the limit value, the amplified bridge output voltage and the circuit detect the set voltage, through the voltage comparator, the square wave generator outputs a set of square wave signals to control the sound, Light detection circuit, the buzzer produces continuous sound, the light-emitting diode flashes, and a detection signal is issued. From the principle of the combustible gas detector, it can be seen that if electromagnetic interference occurs, the detected signal will be affected, and data deviation will occur; if there is a collision or vibration, which will cause the equipment to be disconnected, the detection will fail; if the environment is too humid or the equipment is flooded, it may also cause The combustible gas detector is short-circuited, or the line resistance value changes, and a detection failure occurs.
In summary, it is the component of the combustible gas detector. However, due to the different types of combustible gas detectors, we should use different combustible gas detectors in different places. Semiconductor-type combustible gas detectors should be used in places where coal gas, natural gas, and liquefied gas are used, and catalytic combustible gas detectors should be used in industrial places that emit combustible gas and combustible steam.
