Combustible Gas Detectors - Overview

Combustible gas detectors are among the simple safety protection equipment required whenever there is certainly has potential explosive gas in its plant application.

When it comes to dealing with combustible gases, it is important for those doing so to have a comprehensive knowledge of any combustible gases that they will come in contact with. One area of knowledge that is immensely important is what is known as the LEL. LEL stands for “lower explosive limit.” Basically, a combustible gas will only ignite when it is within a specified range. In other words, too much or too little gas will not ignite. The lower end of that range is the LEL and the higher end of the range is known as the UEL or upper explosive limit.

The minimum concentration of a flammable gas in air capable of igniting is called the Lower Explosive Limit, or LEL. This limit varies with the type of gas and with the oxygen concentration of the air in which the flammable gas is mixed. Sensors designed to detect the dangerous presence of combustible gases are therefore called “LEL sensors.” LEL monitors are used whenever there is a high probability of explosive gases present in the air. These areas are referred to as classified areas in industry and are precisely defined for safety engineering purposes.

You will find two varieties of LEL gas sensors available in marketplace today. The first sort is Catalytic-type gas sensor consist of two elements: a detector element which contains catalytic material and is sensitive to combustible gases, and a compensator element which is inert. The 2nd sort is the Infrared (IR) detection method is based upon the absorption of infrared radiation at specific wavelengths as it passes through a volume of gas.

Catalytic-type gas sensor is commonly utilised in a variety of businesses and generally implemented as single-point detectors for combustible gases. This will burn only on the detector element, causing a rise in its temperature and, as a consequence, a rise in its resistance.

Advantages of Catalytic-type gas sensor detectors are comparatively very low unit cost, simple and maintenance cost are lower in comparison to other Combustible gas detection sensors.

On the flip side, infrared type gas sensors are based upon the ability of some gases to absorb IR radiation. Many hydrocarbons absorb IR at approximately 3.4 micrometres and in this region H2O and CO2 are relatively transparent. As mentioned earlier, there are some hydrocarbons and other flammable gases that have poor or no response on a general-purpose IR sensor.

Some important advantages of Infrared type of Sensors are Immunity to contamination and poisoning, as consumables (source and detector) tend to outlast catalytic sensors & they can be calibrated less often than a catalytic detector.

Once you have established which combustible Gas Detector you have to commission, browse these hints. You want a brief research prior to making any decision. Listed here are hints.

Determine certainly your precise requirements of a combustible gas sensor

While IR detectors do offer enhanced reliability due to their fail-to-safe style, immunity to poisons, and ability to function without oxygen, catalytic detectors offer application flexibility, simple maintenance, and low replacement costs.

Both technologies are reliable, fast detecting and accurate. Neither is necessarily the answer to everything, and in most plants, a combination of both types is the correct and sensible solution.

There is clearly a strong need for both catalytic and IR gas detectors; it’s important to understand your specific needs and requirements before making a decision.