Three methods of sampling and detection of gas detectors that must be known
Gas detector is a kind of dangerous gas protective equipment. It can detect the concentration of toxic and harmful substances in our work. When the gas concentration exceeds the safety line, an alarm will be issued to effectively remind the operator. The gas detector has three sampling and detection methods. Let's take a look.
1. Diffusion sampling
Diffusion gas detectors use natural airflow to slowly flow gas into the instrument with the free flow of air for detection, so as to obtain results.
Diffusion gas detector can check whether there are toxic and harmful substances in the air in real time and accurately. Diffusion gas detectors are typically used in open locations such as open job shops. This method is affected by environmental detection, such as ambient temperature, wind speed, etc. Since there is no suction pump, the sampling speed of the diffusion gas detector is slow, and the detection results are easily interfered by external factors such as wind speed and temperature in the detection environment, and the results will have certain errors.
2. Pump suction sampling
The pump suction gas detector has a built-in micro suction pump, which is activated by the power supply to extract gas from the sampling point area, and then send the sample gas into the gas detector for detection.
Pump-suction gas detectors are generally suitable for places where some people are not suitable to enter, where it is not easy to enter, or where the operator must be tested before entering. Such as tunnels, pipelines, sewers, agricultural closed granaries, railway tank cars, tanks, etc., the pump suction detector can be installed with a long tube on the air pump for ventilation, and long-distance suction sampling. The detection speed is fast, the precision is high, and it can be measured at a long distance, which is the advantage of the pumped gas detector.
3. Pipeline sampling
In addition to diffusion and suction sampling, fixed gas detectors also have a pipeline sampling.
Pipeline gas detectors have threads on one end of the probe. When installing, open an opening of the same size on the pipe, and the probe is closely connected with the pipe without air leakage. In this way, real-time detection inside the pipeline is realized. The pipeline detector is suitable for the environment with low pipeline flow rate and normal temperature and pressure.
