Infrared Technology

GasSecure develops wireless infrared gas detectors based on its proprietary MEMS (Micro Electro Mechanical System) technology and holds a number of patents relating to its proprietary measurement technique.

The GS01 detector utilises infrared (IR) absorption spectroscopy. This method for measuring gas concentration is based on the absorption of IR radiation at gas-specific wavelengths in a volume containing the target gas and is rooted in the principles expressed in the Beer-Lambert Law.

In the GasSecure approach, a MEMS optical filter selects the correct wavelengths for the gas and reference measurement from the incoming broadband light. This filter is a patented silicon component proprietary to GasSecure. By applying a control voltage to the MEMS chip it is switched between the gas state and the reference state. In the gas state, a wavelength area where hydrocarbons do absorb light is focused onto a single photodetector. In the reference state wavelengths, where hydrocarbons do not absorb, are focused onto the same detector. Note that the reference state is composed of two spectral areas located to the left and right of the gas state wavelength position, hence the term triple-wavelength detection.

Filter curves for gas state (green) and reference state (purple)

The MEMS chip serves a number of purposes namely dispersing and focusing light and switching between two optical states and thereby enables a true single-beam design i.e. the light path and all optical components are the same for the gas and the reference measurement. Triple-wavelength detection and single-beam design – both unique to the GS01 gas detector - are the key reasons why GasSecure can guarantee lifetime calibration for their product.

MEMS chip as used in the GS01

For further information, please refer to our technical paper on reliable infrared gas detection, which is available in Downloads.