What is the core component of the gas detector?
Gas detector is one of the most commonly used detection instruments in industrial production, which can detect the concentration of toxic and harmful substances in our work, detect the types of gases existing in the environment with gas detector, and use corresponding safety protection articles according to its detection results. So do you know what is the core component of the gas detector?
Core components of gas detector:
The core component of the gas detector is the gas sensor, which can detect the gas concentration, temperature and humidity and other parameters, and convert the gas concentration signal into an electrical signal. And then the concentration information is displayed by a display device. In addition to sensors, the gas detector also includes detection motherboard, power supply device, alarm device, sampling device, display device, etc. Each part is very important and indispensable.
As the core component of the gas detector, the gas sensor has different detection principles according to the types of the gas to be detected, the detection accuracy and the measurement range. The common types in the market are catalytic combustion gas sensor, electrochemical gas sensor, thermal conductivity gas sensor, infrared gas sensor and PID photoionization sensor.
The most commonly used sensor for detecting combustible gas is catalytic combustion type, which has the characteristics of good linear output signal, low price and no cross interference from other gases. Based on the principle of Wheatstone bridge, the measured gas can burn flameless with the inductive resistor, and the high temperature changes the resistance of the inductive resistor, breaking the bridge balance, thus outputting a stable current signal.
The commonly used sensor for detecting toxic gases is electrochemical, which has the advantages of stable performance, low power consumption, good accuracy and no pollution by other gases, and can detect most toxic and harmful gases. This kind of sensor can react with the measured gas and generate an electrical signal proportional to the gas concentration.
Infrared gas sensor uses the selective absorption properties of different gases to near infrared spectrum and the relationship between gas concentration and absorption intensity to determine gas concentration, which has a series of advantages such as long service life, higher sensitivity, better stability and convenient maintenance.
PID photoionization gas sensor ionizes gas into positive and negative ions that can be detected by detector through ultraviolet light source, and then converts the detected charge into current signal, which is amplified and converted into gas concentration value through corresponding algorithm. This kind of gas sensor has high accuracy, can detect ppb level, good stability, no damage to gas, and fast response. It is widely used in detecting VOC volatile organic compounds, but its price is also relatively high.
