How Many Different Types Of Gas Detectors Are There?

Gas detectors are many and varied as they are designed to operate in a wide range of different environments. However, despite the fact that they might make use of different designs, their goal is the same when it comes to measuring gas concentrations for safety or analysis.

Here, CEM Solutions take a look at some of the most commonly used gas detectors and where they are put to best use.

What is a gas detector?

A gas detector is designed to monitor the concentration of gas in a particular environment and tends to be used in industries such as mining, quarrying, chemical refining, automotive facilities and construction. This can help to show where a build-up of a particular gas might have occurred, or to identify any gas leaks that could cause a hazard to those in the area. These gas detectors can then alert people to any potential problems and allow swift and effective action to be taken in order to keep everyone safe.

Electrochemical gas detectors

An electrochemical gas detector is designed to detect toxic gases such as carbon monoxide, hydrogen sulphide and chlorine. This makes use of a sensor through a membrane that covers an electrode. As oxygen diffuses into the sensor, an electrochemical reaction occurs, and the electrode produces an electric signal proportional to the amount of gas that it is able to detect. These types of gas detectors are most commonly used in areas which suffer from poor air quality, such as manufacturing, chemical and food industries.

Catalytic bead gas detectors

A catalytic bead gas detector is used to detect flammable gases. As combustible gases produce heat, they oxidise and this change in resistance of the bead within an embedded coil measures the gas concentration. This temperature change is then converted within the sensor to a readable signal. Flammable gases and vapours are most often present in the mining, oil, gas, waste management and construction industries, and so these catalytic bead gas detectors are extremely useful in these environments.

Photoionisationa detectors (PIDs)

Volatile organic compounds (VOCs) are picked up by PID detectors. These VOCs are highly toxic and usually combustible as well meaning that there is a distinct danger to life even when they are found in low concentrations. The PID detector contains an ultraviolet lamp that can emit photons. The electrical current that is generated measures the target and the current converts to the concentration of VOCs that are present. These tend to be preferred where there is a potential spill of hazardous materials such as oil, gasoline, benzene or other emergency leak situations.

Infrared gas detectors

These infrared gas detectors use sensors to detect a wide range of hazardous gases. These can include hydrocarbons and carbon dioxide, amongst others. They are able to convert the invisible infrared radiation that is picked up into visible infrared images. The extreme sensitivity of the devices means that it is possible to identify and quantify the presence of a leaking gas extremely quickly, and so they tend to be used where natural gas leakage is a common problem, such as the petrochemical industry, gas transportation, power generation and aviation maintenance.

There are many other types of gas detectors, but most of them work on these four main principles. They can then be adapted to particular environments and converted into fixed or wearable options depending on what they need to monitor. It is therefore important to assess the risk in a particular area or industry to decide which gas detector is best suited for the most likely problems. These gas detectors can then be at their most effective when it comes to keeping people and property as safe as possible.