Gas detector is equipment for gas leak detection in specific operation area and alarm the gas concentration level . It is possible to detect and measure combustible gas, toxic gas, oxygen in confined space, or specialty gas to ensure safety working in the factory. 

Gas detector is classified for 2 categories as the following :

1. Portable gas detector is one the personal protective equipment, handheld type a worker can carry or attach to the body, to measure gas around a moving worker to prevent accidents cause from explosion, inhale toxic gas, or indispensable oxygen.
2. Fixed gas detector system compose of gas detector sensor, indicator and alarm unit to indicate the concentration of gas, which is specific design and install upon to customer requirements to measure the gas concentration around installation point in hazardous area. There is a system configuration that intensively monitors the signals that each indicator/alarm unit outputs in the monitoring system.

Additionally, target gas is able to classified for 4 groups as the following :

• Combustible gas such as Hydrocarbon gas, Methane (CH4), Isobutane (i-C4H10), Propane (C3H8), Hydrogen (H2), Solvent, etc.
• Toxic gases such as Anhydrous Ammonia (NH3), Carbon Monoxide (CO), Chlorine (Cl2), Hydrogen Fluoride (HF), Hydrogen Sulfide (H2S), Sulfur Dioxide (SO2), etc.
• Oxygen (O2)
• Specialty gases such as Hydrofluorocarbon (HFCs), Carbondioxide (CO2), Sulfur Hexafluoride (SF6), etc.

To ensure safety, gas detector and sensor are recommended to check and calibration at least once a year.