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All people are living and working in potentially dangerous environments. Whether travelling in a vehicle, out for a walk, or at work in a mine or factory, people are in environments where the air is polluted and potentially harmful to health – gas monitoring is essential in understanding the levels of gas pollution being emitted into the atmosphere from static sources, or present at any given location, and informing decisions on preventative measures to reduce emissions and make these environments safer.

Let’s go over a few gas monitoring basics and delve into what makes them so useful across such a vast array of industries applications.

What Are Gas Monitors?

Gas monitors are devices that continuously check air quality in enclosed and open spaces, extremely useful in industries where dangerous gases may be present in the air. A good example is the mining industry where the presence of methane can make air flammable – using gas analysers protects employees by helping them stay aware of air quality at all times.

Another example is a factory that emits fumes into the atmosphere from their industrial process. These emissions could contain harmful substances such as carbon monoxide or sulfur dioxide, at concentrations which are harmful to humans, plants and animals. To prevent these scenarios, it is essential that gas monitoring devices are operational on-site.

Besides these instances, gas monitors are also often used by first responders, firefighters, maintenance professionals and are a common fixture in the tool-set of utility crews.

What Does a Gas Monitor Detect?

One of the ways in which gas monitors differentiate is according to the types of gases they detect. Some are specifically made for detecting a single gas, whereas others have the ability to detect a multitude.

Gas analysers can detect methane, nitrogen oxides, sulfur oxides, ozone, hydrogen chloride, ammonia, and a variety of other gases. They not only detect whether a particular gas is present in the air but can they also show the percentage or concentration of the gas in the air. This is especially important as there are limits that must be adhered to according to national and state standards as well as site specific environmental licenses.

How Do Gas Monitors Work?

Different gas monitors work in different ways – ones that serve to detect combustible gases will function in a different way to those designed to detect toxic gases.

Combustible Gases

Gas monitors that were designed to detect the presence of combustible gases use catalytic oxidation or infrared sensors. Systems relying on catalytic oxidation have a sensor that is built with a platinum-treated wire coil in the majority of cases.

Coil resistance changes when it reacts to a combustible gas. This occurs because of the temperature change during the oxidation process. This process occurs naturally once the combustible gas comes in contact with the catalytic surface.

On the other hand, infrared sensors are also used for combustible gas detection. The receiver and transmitter alter how they operate when a gas is present in the air. When an IR sensor is used, the gas monitor can identify the gas in the air.

Toxic Gases

Toxic gases are another threat that can be present in the air of an environment. Different technologies are deployed for detecting things like carbon monoxide, sulfur oxides and nitrogen oxides.

Gas Filter Correlation (GFC) can be used for measuring carbon monoxide. This works by comparing infrared energy absorbed by a sample to that absorbed by a reference gas according to the Beer-Lambert law.

UV fluorescence can be used for measuring sulfur dioxide, and chemiluminescence can be used for nitrogen oxides. Newer developments include cavity attenuated phase shift (CAPS) for nitrogen oxides.

Specialized technologies include cavity ring down spectroscopy (CRDS) for trace level detection (parts per trillion), and Fourier Transform Infra-Red (FTIR) for simultaneous real-time measurement of up to 50 gases.

What Are The Advantages Of Gas Monitors?

Gas monitors should be used in all industries with a high chance of certain gases being present in the air. They can be either portable or fixed, depending on the application and requirement.

Being able to measure toxic and combustible gas levels in real-time ensures the safety of employees, the general public, and the environment. It also allows for reporting to authorities and  adherence to environmental licenses, which prevents breaches and costly fines.

Which Gas Monitors Can You Find at Thomson Group And Where?

Thomson Group offers gas analysers Australia-wide. You can find our offices in the following regions.

  • NSW
  • ACT
  • QLD
  • WA
  • VIC

Furthermore, you can find different gas monitoring systems on our website. Feel free to explore the following:

Reach out to us and one of our professionals will get back to you to help you find the perfect gas monitoring system.


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