Leak detector

A new sensor system uses fibre-optic technology to detect rocket-fuel leaks, helping to avoid waste, improve reliability and protect personnel.

The technology was developed by Torrance, California-based InnoSense through a contract from the US Missile Defense Agency (MDA). The contract called for the company to develop a hydrazine leak detector for the sea-based Kinetic Energy Interceptor (KEI) program.

In missile applications, detecting leaks of hydrazine-based fuel is critical for several reasons. The risk of fire from leaked fuel is obvious, but more likely than a fire or explosion, is the slow depletion of fuel over time, which degrades the performance and reliability of the missile system.

Existing hydrazine detectors require maintenance, such as battery replacement, and some can’t withstand the harsh environments where the missile systems are deployed. In addition, some are not sufficiently sensitive.

InnoSense addressed all of these concerns with its fibre-optics-based sensor. Because the sensor is all-optical, there are no batteries to replace over its 10-year expected lifetime. The sensor can be calibrated to detect leaks in the parts-per-billion or parts-per-million range. In addition to its capability of sensing a static level of fuel molecules in the environment, it can also be configured to sense the rate of accumulation over time.

The device has met MDA’s temperature range requirements of -46°C to 71°C. The sensing unit is also small and lightweight, so users can easily deploy as many units as required.

Future iterations of the system could monitor other types of industrial chemical leaks and aid environmental monitoring.

Read more about the design of the sensor at: