Fault Analysis of Flammable Gas Detectors
The combustible gas detector consists of two parts: detection and detection, with detection and detection functions. The principle of the detection part of the combustible gas detector is that the sensor of the instrument uses a detection element, a fixed resistor, and a zero potentiometer to form a detection bridge. The bridge uses platinum wire as a carrier for catalytic elements. After being powered on, the temperature of the platinum wire rises to the working temperature, and air reaches the surface of the element through natural diffusion or other means. When there is no combustible gas in the air, the bridge output is zero. When the air contains combustible gas and diffuses onto the detection element, flameless combustion occurs due to catalytic action, causing the temperature of the detection element to rise and the platinum wire resistance to increase, causing the bridge circuit to lose balance. As a result, a voltage signal is output, which is proportional to the concentration of combustible gas. The signal is amplified, analog-to-digital converted, and displayed on a liquid display to show the concentration of combustible gas. The principle of the detection part is that when the concentration of the combustible gas being measured exceeds the limit value, the amplified bridge circuit outputs a voltage and the circuit detection set voltage. Through the voltage comparator, the square wave generator outputs a set of square wave signals to control the sound and light detection circuit. The buzzer produces continuous sound, and the light-emitting diode flashes to emit a detection signal. From the principle of combustible gas detector, it can be seen that if electromagnetic interference occurs, it will affect the detection signal and cause data deviation; If there is a collision or vibration that causes the equipment to break, the detection will fail; If the environment is excessively humid or the equipment is flooded, it may also cause a short circuit in the combustible gas detector or a change in the resistance value of the circuit, resulting in detection failure.
