Not all infrared monitors are created equal

‘Photoacoustic infrared technology enables gases to be detected at extremely low levels due to its inherent stability and reduced cross—sensitivity.’‘There is no zero point involved—providing more accurate and reliable readings.’ By Allan Roczko

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When protecting your employees and operational processes from toxic and combustible gases, it’s critical to choose a gas detector that provides the most accurate and reliable monitoring possible. With so much at stake, using the most advanced technology possible is your best option. Since there are so many types of facilities, gas detection needs can vary greatly. Some facilities require monitors to identify gases at the lowest possible levels. Other facilities use combustible gases that require explosion—proof monitors. It’s possible to utilize a single gas detection monitor for all of the challenges mentioned above—one that utilizes photoacoustic infrared technology.

Photoacoustic infrared technology enables gases to be detected at extremely low levels due to its inherent stability and reduced cross—sensitivity. To understand photoacoustic infrared technology, it is important first to understand how traditional infrared technology works. Infrared detection uses infrared light to detect the presence of gas. When a gas is exposed to the infrared light, it absorbs some of the light’s energy. Specific gases absorb light at specific wavelengths, allowing gases to be identified by measuring the absorption of light at these wavelengths. Optical filters are used to pass only the particular band of wavelengths for the gas of interest. Infrared technology has been used for many years with great success for ambient gas level detection. Historically, one of the most commonly used forms of infrared detection has been absorptive infrared technology. In an absorptive infrared monitor, a sample of the gas in question is introduced into the monitor’s measurement chamber and exposed to infrared light. Simultaneously, a sample of an inert gas (usually nitrogen) is present in a separate measurement chamber within the same monitor, and is known as the reference gas. By using an inert gas, one ensures that no absorption takes place and that all the infrared light passes through the chamber. This provides an accurate baseline from which to measure light absorption by the gas in question, as the detector compares the amount of light transmitted through the sample and the reference cells. The monitor can determine the concentration of gas present in the sample by the ratio of light that is transmitted by the sample gas to the light that is transmitted by the reference gas. For example, if the amount of light transmitted through both cells is equal, then the sample cell does not contain the gas of interest. Conversely, the difference between the amount of light transmitted through the sample and reference cells can be used to quantitatively determine the concentration of gas in the sample cell.

How It Works



Benefits of Photoacoustic Infrared Monitors


