In this article, we'll be discussing the four main types of gas detectors: electrochemical sensors, catalytic sensors, infrared sensors and photoionization sensors.
Available as either fixed or fully portable gas detectors they are commonly used for the following gases, Hydrogen Sulphide, Carbon Monoxide, Oxygen and combustibles (%LEL).
Using a 4 gas monitor can protect your workers in any environment by assessing the four main gases Oxygen (O2), Carbon Monoxide (CO), Hydrogen Sulfide (H2S), Methane (CH4), or other combustible gases you're checking for.
There are two types of widely used LEL sensors; catalytic “Wheatstone bridge” or infrared (IR) sensors.
The Lower Explosive Limit (LEL) varies from gas to gas, but for most flammable gases it is less than 5% by volume. This means that it takes a relatively low concentration of gas or vapour to produce a high risk of explosion.
An LEL Detector or LEL Meter detects dangerous levels of a combustible gas or solvent vapor in air, expressed in percent Lower Explosive Limit, or LEL. An LEL Detector is an integral part of a complete gas detection system and can be referred to as a Gas Detector or just a fixed gas detection system.
Gas stations typically carry three octane grades. State laws regulate which octane levels can be listed as premium, midgrade or regular. Typically “regular” gas is 87 octane, “midgrade” is 89 octane and over 91 octane is “premium” gasoline. Some states label top-tier gasoline with 93 octane as “ultra” gas.
It is best to install a gas detector in every room where gas-consuming appliances are installed.
Catalytic diffusion sensors are the most widely used devices for the detection of combustible gases and vapors.
Pellistor/Catalytic Bead (CB) Industrial Gas Detectors
This type of sensor has been in use for nearly a century and works by measuring the temperature difference between two beads – one inert one and one coated in a chemical catalyst. As they are heated, the one with the catalyst will heat more.
IEC 60079-29-1 Ed 2.0, which relates to the performance requirements of detectors for flammable gases and. IEC 60079-29-2 Ed 1.0, which refers to criteria for selection, installation, use and maintenance of detectors for flammable gases and oxygen.
A chromatography detector is a device used in gas chromatography (GC) or liquid chromatography (LC) to detect components of the mixture being eluted off the chromatography column. There are two general types of detectors: destructive and non-destructive.
Safe-T-Alert 12V Gas Detector Suitable For LPG & Natural Gas.
Catalytic diffusion sensors are the most used devices to monitor flammable and explosive gas or vapors.
Install your natural gas detectors in locations close to sources of natural gas. This includes, placing them in any room with windows or a gas appliance such as your kitchen and your basement. When adding to a room with windows, be sure to position natural gas detectors higher than all doors and windows.
LP gas detectors should be mounted as low as possible (typically 10 cm (4 inches) above the floor) and in a place where air movements are not impeded by furniture.
Gases. The most abundant naturally occurring gas is nitrogen (N2), which makes up about 78% of air. Oxygen (O2) is the second most abundant gas at about 21%. The inert gas argon (Ar) is the third most abundant gas at 0.93%.
20% LEL is the High Alarm, a distress signal. Not explosive yet. 100% LEL means the gas concentration has reached the lower explosive limit and became explosive.
The LEL of a gas is the lowest concentration of that gas which can combust. A reading in %LEL measures the percentage of that LEL value. For example, for methane, the LEL is 5% by volume. 50% LEL is half of that value, or 2.5% by volume.
LEL sensors measure percent of LEL. For example, Gasoline has an LEL of 1.4%. Therefore, 100% of LEL is 14,000 ppm of gasoline, 10% of LEL is 1,400 ppm of gasoline and 1% of LEL is 140 ppm of gasoline.