Classification of Hazardous Gas Detection and Alarm Devices
1. Classified by usage method:
① The portable harmful gas detection and alarm instrument integrates sensors, measurement circuits, displays, alarms, rechargeable batteries, and vacuum pumps into one body, making it a compact and lightweight instrument that is easy to carry. It is pump suction sampling and can be used for detection anytime and anywhere. Pocket sized instruments are a type of portable instrument that typically use diffusion sampling without an air pump, are powered by dry batteries, and have a very small size. ② Fixed harmful gas detection and alarm devices are fixed on site to continuously and automatically detect corresponding harmful gases (vapors). When harmful gases exceed the limit, they will automatically alarm, and some can also automatically control exhaust fans, etc.
Fixed instruments are divided into two types: integrated and split.
Integrated fixed harmful gas detection and alarm device: Similar to portable instruments, the difference is that it is installed on site, powered by 220V AC, continuously and automatically detects and alarms, and mostly adopts diffusion sampling. Split type fixed harmful gas detection alarm: The sensor and signal transmission circuit are assembled in an explosion-proof enclosure, commonly known as a probe, and installed on site (in hazardous areas); The second part includes data processing, secondary display, alarm control, and power supply, assembled into a controller, commonly known as a secondary instrument, installed in the control room (safe place). Probe diffusion sampling detection, secondary instrument display alarm.
2. Classified by the tested object and sensor principle
① Combustible gas detection and alarm device (abbreviated as explosive detector, an instrument that detects multiple combustible gases) catalytic combustion combustible gas detection and alarm device, which detects various combustible gases or vapors. Electrochemical toxic gas detection and alarm device, capable of detecting CO, H2S, NO, NO2, CL2, HCN, NH3, PH3, and various toxic organic compounds. Infrared combustible gas detection and alarm device, capable of detecting various combustible gases (depending on filtering technology). Semiconductor based combustible gas detection and alarm device, capable of detecting various combustible gases. Thermal conductivity combustible gas detection and alarm device, used to detect hydrogen gas with significant thermal conductivity differences from air. Toxic gas detection and alarm device (referred to as a toxin detector, an instrument for detecting a toxic gas) is a photoelectric ionization toxic gas detection and alarm device that detects organic and inorganic compounds with ionization potentials less than 11.7 eV. Infrared toxic gas detection alarm, detecting CO, CO2, etc. Semiconductor based toxic gas detection and alarm device, capable of detecting CO, etc.
