Gas Monitors, Gas Sensors, Gas Detectors

Guidelines for Choosing a Fixed Gas System - Flammable Gas Hazards Requiring Gas Monitors, Gas Sensors, Gas Detectors
1. Fixed Gas Detection
Industrial processes increasingly involve the use and manufacture of highly dangerous substances, particularly flammable, toxic and oxygen gases. Inevitably, gas occasionally escapes, which creates a potential hazard to the industrial plant, its employees and people living nearby.
 
2. Detection Principles
Flammable Gas Hazards
Combustion is a chemical reaction in which oxygen is combined rapidly with another substance resulting in the release of energy. There is only a limited band of gas/air concentration which will produce a combustible mixture. This band is specific for each gas and vapor and is bounded by an upper level, known as the Upper Explosive Limit (or the UEL) and a lower level, called the Lower Explosive Limit (LEL).
 
Toxic Gas Hazards
Toxic gases are poisonous and can be dangerous to life at very low concentrations. The measurements most often used for the concentration of toxic gases are parts per million (ppm) and parts per billion (ppb). For example 1 ppm would be equivalent to a room filled with a total of one million balls and one of those balls being red. The red ball would represent 1 ppm. More people die from toxic gas exposure than from explosions caused by the ignition of flammable gas.