Can detect 4-6 gases at the same time, and the unit can be switched freely It is used for 24-hour continuous online monitoring of the concentration of various gases on site, temperature and humidity measurement, on-site concentration, and remote signal transmission. It is suitable for detecting gas concentration in pipelines or in confined spaces and atmospheric environments; Gas leakage or various background gases are high-concentration single gas purity of nitrogen ., Manufacturer: CVFRDD