Fixed gas detectors are designed specifically for continuous monitoring of ambient air for industrial, commercial or residential applications. Its main function is to provide first level alert to workers or occupants of potential danger of poisoning by toxic gas exposure, asphyxiation due to lack of oxygen or explosion caused by combustible gases. Generally, fixed gas detector will be mounted near the process area of a plant or factory, or a protected area within a laboratory, commercial HVAC, residential kitchen and etc.