The fundamental difference between portable and fixed gas detectors
Portable combustible gas detectors are divided into two types: pump suction type and diffusion type.
The diffusion gas detector is the gas in the detection area flows freely in the air and slowly flows the sample into the instrument for detection. This method is affected by the detection environment, such as ambient temperature and airflow.
The diffusion gas detector is characterized by a low cost.
The pump-suction gas detector is equipped with a small air pump, and its working mode is that the power supply drives the air pump to sample the gas in the area to be detected, and then sends the sample gas to the instrument for detection.
The pump-suction flue gas analyzer is characterized by fast detection speed and can perform long-distance measurement in dangerous areas to maintain the safety of personnel. Others are the same as diffusion gas detectors.
The working principle of the pumping gas detector is basically the same as that of the diffusion gas detector. The carbon dioxide analyzer detects the sample gas through the sensor of the instrument and then magnifies and converts the corresponding value into the corresponding value shown on the display. Catalytic combustion sensors are commonly used in combustible gas detectors, and electrochemical sensors are commonly used in toxic gases.
Fixed gas detector
This is a gas detector used more in industrial installations and production processes. It can be installed at a specific detection point to detect specific gas leaks. The fixed detector is generally a two-body type. The detection head composed of sensor and transmitter is installed in the detection site as a whole, and the secondary instrument composed of the circuit, power supply, and display alarm device is installed in a safe place for easy monitoring. Its detection principle is the same as that described in the previous section, but it is more suitable for the continuous, long-term, and stable characteristics required by fixed detection in terms of process and technology. They should also be selected according to the type and concentration of the gas on-site, and at the same time, they should be installed at the most likely leaking part of the specific gas. For example, the most effective height of the sensor should be selected according to the specific gravity of the gas.