How to choose a gas detector in a confined space?
Before entering, personnel enter the confined space (such as storage tanks, sewers, septic tanks, agricultural grain storage bins, tunnels, etc.) to work. Harmful gas concentration detection in the working environment must be carried out. Here, it is necessary to use a gas detector to solve the problem. The gas detector is also called a gas alarm, which uses a gas sensor to detect the type, composition and content of the gas in the environment.
1. It has a built-in pumping function, so that it can be detected by non-contact and divided parts. The gas distribution and gas types are very different in different parts of the confined space.
2. It can detect the concentration of various gases at the same time, so as to detect dangerous gases distributed in different spaces, including inorganic gases and organic gases;
3. It can monitor the oxygen concentration function to prevent hypoxia or oxygen enrichment;
4. The appearance of the gas detector must be compact, easy to operate and read, and not affect the normal work of workers.
When you choose a portable gas detector, it is best to choose an instrument with the function of switching each sensor separately to prevent the damage of one sensor from affecting the use of other sensors. At the same time, in order to prevent the blockage of the suction pump due to water inflow, etc., the safety factor of the instrument designed with a smart pump design with a pump stop alarm will be higher.
What is the working principle of the gas detector sensor?
Generally speaking, electrochemical sensors are widely used for most gas detection, such as the detection of sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone and other gases, and electrochemical sensors are generally used. Electrochemical sensors are characterized by simple operation, easy to use, low price and affordable, and good accuracy and response time, but they are more affected by the environment. Laser is generally used for PM2.5, and PID or FID for VOCs.
The working principle of the electrochemical sensor is simple, it reacts with the measured gas, and the gas concentration is determined by using the relationship between the generated current intensity and the concentration in a certain range; PM2.5 uses laser scattering technology, through the scattering of laser light, to determine The concentration of particulate matter in the air; VOC is slightly higher-end, both PID and FID are available. Although FID has high precision, the cost is also a bit high. Generally, PID is used. PID is actually a photoionization detector. The light energy ionizes the gas molecules to generate a current. After the current is amplified and processed, the gas concentration can be measured according to the current intensity.
