Oxygen Sensors for On-Board Inert Gas Generation Systems

Minimising Explosion Risk in Aircraft Fuel Tanks

In aviation, safety is paramount—and when it comes to aircraft fuel systems, minimising the risk of explosion is a top priority. One of the most effective ways to achieve this is by reducing oxygen levels within the fuel tank to near-zero. By removing oxygen from the fire triangle, the potential for ignition is virtually eliminated.

Although fuel tank explosions in civil aviation are extremely rare, manufacturers like Boeing and Airbus continue to invest heavily in advanced safety systems. Fire protection is a core consideration in the design, testing, and certification of modern aircraft, and systems that prevent ignition within fuel tanks are a critical part of that process.

Proven Methods for Inerting Fuel Tanks

Fuel tank inerting has long been a standard safety feature in military aviation. Techniques such as liquid nitrogen injection, halon systems, and the use of reticulated foams have successfully reduced fire risks in combat environments. These approaches work by introducing inert gases that displace oxygen, creating an environment where combustion is not possible.

This same principle is applied in civil aviation through the use of On-Board Inert Gas Generating Systems (OBIGGS), which have become the standard approach for keeping fuel tanks safe under all conditions.

SST’s Role in OBIGGS: Precision Oxygen Sensing

At the heart of OBIGGS lies the need for accurate, responsive, and durable oxygen sensors. SST’s zirconium dioxide oxygen sensors are specifically designed for demanding environments like aircraft fuel systems, where precision and reliability are non-negotiable.

Our sensors are integral to OBIGGS control systems in a wide range of aircraft, including those manufactured by Boeing and Airbus. Their consistent performance ensures that inerting systems function exactly as required, maintaining oxygen levels low enough to render fuel vapours non-flammable.

How OBIGGS Works

The OBIGGS process begins with air drawn from the engine or bleed system, which is then conditioned to the correct pressure and temperature. This air is passed through one or more Air Separation Modules (ASMs), where oxygen is removed using a porous membrane.

The result is a nitrogen-enriched air (NEA) stream, which is delivered into the aircraft’s fuel tanks. This inert gas forms a protective blanket over the fuel surface, displacing oxygen and keeping the vapour space below flammable limits. SST’s oxygen sensors monitor this process, ensuring safe and stable operation throughout each phase of flight.

Built for Reliability in Aerospace Environments

SST’s zirconium dioxide oxygen sensors are engineered for continuous operation in extreme environments. They are solid-state, with no consumable parts, and deliver fast response times and long-term stability. Designed to withstand temperature variations, vibration, and pressure changes, our sensors are ideally suited for integration into modern aircraft safety systems.

Need technical advice or product recommendations for OBIGGS or fuel system safety?
Call our team on +44 (0)1236 459 020 or email us at sales@sstsensing.com to speak with an expert.