The standard 4-gas detector is a multi-gas detector, measuring 4 types of gas at the same time: Explosion (Ex or LEL); O2; CO and H2S. These are 4 gases that need to be measured in most applications working in confined spaces.
There are 2 main options for 4-gas detector which are pump-free diffusion measurement type and type with suction pump for remote measurement or external measurement. Suction pump applications are underground roads, tunnels, tanks, tanks, silos, tanks and any other enclosed areas …
Popular 4-gas detector:
MSA Altair 4XR gas detector, MSA USA, diffusion measurement. This type of many high-end functions.
GasAlert MicroClip XT/XL/X3 gas detector, BW Honeywell USA, diffusion measurement. This is the simplest line and the most competitive price. GasAlertMax XT II, BW Honeywell, suction pump meter. This is the most common type in the line with suction pumps. The machine is durable, stable, easiest to use and the price is also the most economical. The GasAlert Max XT II can remove the front cover to switch to diffusion measurement.