Gas Detectors

In a lot of manufacturing processes as well as metal working and refining processes, potentially harmful gases are released as a by-product of these procedures. In order to keep personnel safe, gas detectors - also known as gas monitors - are a portable device that work to detect levels of harmful gases as well as detecting gas leaks. Here at Cromwell, we have a wide range of gas detectors from leading brands such as MSA and TPI.

Why gas detectors?

Usually a handheld device, gas detectors are ideal for use when working with flammable materials on a site where the presence of certain gases in a high concentration may be harmful or volatile to human life. By detecting potentially harmful levels of gases, gas detectors can prevent serious injury to personnel. Their portable nature makes them useful when on site and they can be used to detect varying types of gas depending on your product selection. They are also extremely handy when trying to identify a gas leak.

Gas detector types

Whilst all gas detectors are of course designed for detecting gas, the specific gas varies from product to product. Some models can detect multiple types of gases, whilst others are more specialised to detect a singular gas type only. Below, we've listed the five most common types of gas that can be detected by gas detectors.

• H2S   -   Hydrogen sulfide is highly toxic and flammable, even at low concentrations. It can cause damage to the respiratory system as well as causing irritation to the eyes. Detecting levels of H2S is crucial in the gas and oil industries as it can be found when drilling for oil.

• CO   -   Carbon monoxide is extremely dangerous for humans and is colourless and odourless, making it hard to detect without the use of a gas detector or a carbon monoxide alarm.

• NO2   -   Nitrogen dioxide is extremely harmful to the respiratory system and long term exposure can cause chronic lung disease. It is not flammable as a gas but can lead to combustion at high temperatures. It is often expelled when welding as well as from combustion in engines.

• O2   -   Whilst of course oxygen is essential for life, too much oxygen can actually cause oxygen poisoning, also known as oxygen toxicity. When diving underwater, it is important to regulate the amount of oxygen taken in. Oxygen detectors are primarily used to ensure that there is enough oxygen in the air when compared to the other gas levels in the air.

• SO2   -   Sulfur dioxide can be used to sterilise wine and beer making equipment, but in large quantities can cause respiratory problems. It smells similar to the odour of a just lit match and is colourless. It is commonly a by-product in the petrol refining process as well as metal smelting and paper pulp manufacturing.

FAQs

What type of detector is used for gas?

There are three main types of gas detector, all of which use slightly different technologies to sense and monitor gas levels. Catalytic diffusion sensors . Electrochemical gas detectors possess two electrodes which allow charged molecules to travel through a layer of electrolyte. The gas that is being detected reacts with this and the gas detector produces an electrical signal that matches the concentration of the gas in the air. Catalytic diffusion sensors are used to detect combustible gases by sensing a rise in temperature due to the oxygen burning and reacting with the combustible gas. Photoionisation detectors (PID) are used for detecting volatile organic compounds (VOC). The UV light source on a PID breaks down the VOCs in the atmosphere into their positive and negative ions, feeding back this concentration to the detector to allow you to see the volume of VOCs in the air.