Why Fire Protection in Aviation is Essential: Exploring the Benefits of Zirconia Oxygen Sensors

Zirconia Oxygen Sensors for Fire Protection in Aviation

Introduction

Boeing and Airbus, as well as their suppliers, have been working to reduce the risk of fuel tank explosions in aircraft for many years. Fire protection is an essential aspect of aircraft design, testing, and certification. Fuel tank explosions can occur due to several factors, including electrical faults, lightning strikes, and static discharge.

As a result, airplane manufacturers have focused on developing effective methods to minimize the risk of explosions in aircraft fuel tanks. One of the most crucial aspects of fire protection is the introduction of inert gases into fuel tanks to minimize the concentration of oxygen, which is necessary for combustion.

In this blog, we discuss the measures taken by aircraft manufacturers to minimize the risk of fuel tank explosions in all types of aircraft. It highlights the importance of fire protection in aviation and the various methods used to introduce inert gases into aircraft fuel tanks, including the use of zirconium dioxide oxygen sensors.

Reducing the Risk of Fuel Tank Explosions in Aviation

Fuel tank explosions in aircraft can be catastrophic and are a major safety concern. As a result, manufacturers have been conducting extensive research to find effective ways to minimize the risk of fuel tank explosions in all types of aircraft.

One of the most critical measures taken to reduce the risk of fuel tank explosions is to maintain oxygen levels close to zero. This is achieved by introducing inert gases, which effectively remove oxygen from the fire triangle, thus greatly reducing the likelihood of fire or explosion.

In civil aviation, manufacturers typically use On-board Inert Gas Generation Systems (OBIGGS) to introduce inert gases into aircraft fuel tanks. OBIGGS systems utilize Air Separation Modules (ASMs) that remove oxygen from the air and generate nitrogen-enriched air (NEA) that covers the fuel tank's interior. This NEA, with very low oxygen levels, renders the vapours inside the fuel tank non-flammable, significantly reducing the risk of fuel tank explosions.

In military aircraft, where the risk of fuel tank explosions is even higher, various methods have been used to introduce inert gases into aircraft fuel tanks. These methods include the use of reticulated foams, liquid nitrogen, and halon inerting systems. These systems have been successful in fire prevention systems by utilizing stored gas and gas-generating systems.

To ensure the effectiveness of OBIGGS and other fuel tank inerting systems, it is crucial to have accurate and reliable oxygen sensors to monitor oxygen levels in the fuel tank. PST's range of Zirconium Dioxide Oxygen Sensors are designed specifically for this purpose and are integral to the OBIGGS systems used in Boeing, Airbus, and many other civilian aircraft.

Integrating Zirconia O2 Sensors with Inert Gas and OBIGGS Systems

Zirconia oxygen sensors, also known as zirconium dioxide sensors or solid electrolyte oxygen sensors, offer a solution to the challenges of monitoring oxygen levels in aircraft fuel tanks.

One of the primary functions of integrating zirconia oxygen sensors with inert gas systems is to monitor the efficiency of the inerting process. By continually measuring the oxygen concentration within the fuel tanks or other protected areas, the sensors can provide real-time data on the effectiveness of the inert gas in maintaining a non-flammable atmosphere. This information can be used to adjust the flow of inert gas, ensuring optimal conditions for fire prevention.

While both zirconia oxygen sensors and inert gas systems contribute to fire protection, they work through different mechanisms. The inert gas systems prevent fires by creating an environment where combustion cannot occur, while zirconia oxygen sensors detect fires in their early stages by monitoring oxygen levels. Combining these two systems offers a comprehensive approach to fire prevention and detection, enhancing the overall safety of an aircraft.

Zirconia oxygen sensors can also be used to monitor the health of the inert gas system. An unexpected rise in oxygen concentration could indicate a leak in the system, allowing oxygen to enter the protected areas. By identifying such issues early, necessary maintenance or repairs can be performed promptly, ensuring the continuous and efficient operation of the inert gas system.

PST Zirconium Dioxide Oxygen Sensors

PST designs and manufactures a range of Zirconium Dioxide Oxygen Sensors that are highly reliable and play a crucial role in controlling the OBIGGS as they are designed to withstand the harsh conditions of the aviation environment, such as high temperatures and vibration.

PST's zirconium dioxide oxygen sensors utilize a ceramic-based technology that offers fast response times, high accuracy, and long-term stability. The sensors work by measuring the difference in the concentration of oxygen between the reference gas and the sample gas. The reference gas is exposed to air while the sample gas is extracted from the fuel tank, and the difference in oxygen concentration is measured by the sensor. This information is then fed back to the OBIGGS controller, which adjusts the flow of nitrogen gas into the fuel tank to maintain the desired oxygen concentration levels.

PST's zirconium dioxide oxygen sensors include models that are compatible with different types of OBIGGS and fuel tanks, ensuring that aircraft manufacturers can find a sensor that meets their specific needs. These sensors are also designed to be easy to install and maintain, reducing downtime and maintenance costs for aircraft operators.

Conclusion

The integration of zirconia oxygen sensors in fire protection systems for aviation plays a vital role in ensuring the safety of both civilian and military aircraft. By accurately monitoring oxygen levels within fuel tanks and other protected areas, these sensors enable the effective implementation of inert gas systems such as OBIGGS, significantly reducing the risk of catastrophic fuel tank explosions.

PST's zirconium dioxide oxygen sensors, specifically designed for the demanding aviation setting, deliver dependable, accurate, and long-lasting performance that is critical for upholding a secure and efficient fire protection system for aircraft globally. With the use of these sensors and other safety measures, the risk of fuel tank explosions can be significantly minimized, providing a safer and more secure aviation industry.