Gas sensing technology is an important part of most industrial sectors, be it to detect carbon dioxide (CO2), NOx, or oxygen levels. At 30,000 feet the ability to detect gases, especially oxygen, becomes a necessity.

Process Sensing Technologies (PST) addresses this concern by providing oxygen gas sensors for the Onboard Inert Gas Generation Systems (OBIGGS) integrated into commercial aircrafts, such as those owned and operated by Boeing and Airbus.

Having been used for decades for military aircraft, the OBIGGS create a safer environment by reducing the risk of an explosion within the fuel tank by limiting the presence of oxygen in the headspace of the container to below that of the fuel’s combustion threshold.

PST's zirconia dioxide sensor parts.

PST’s zirconia dioxide sensor parts.

Source: PST

The process behind it involves partitioning an air supply into nitrogen- and oxygen-enriched air (based on molecular weight), with the nitrogen rich air now in circulation within the headspace, the gas is ventilated to lower the risk of fuel vapour flammability.

The risk is further reduced by using a material designed to withstand even harsher conditions, such as the high-pressure conditions present at high altitude or chemical attack from hazardous vapours and fluids.

PST’s flange pinned zirconia dioxide sensor are contained within corrosion-resistant housings of stainless steel and provides an extended temperature range of -100 – 400°C for OBIGGS applications.

Capable of measuring oxygen concentration from 0.1 to 100%, the sensors have been used in OBIGGS technology constructed by both Boeing and Airbus.