Air Sensor for Hydraulic Fluid

Hydraulic systems are vital to aircraft. The Air Force uses approximately 1.5 million gallons of hydraulic fluid per year, resulting in over $15 million in procurement and disposal costs. Hydraulic fluid is usually drained from the aircraft during routine maintenance and disposed of as hazardous waste. Recently the Air Force has started purifying hydraulic fluid for reintroduction to aircraft. These purification systems require an online sensor to measure the quality of hydraulic fluid in real-time. The rapid, on-site ability to measure the quality of hydraulic fluid is essential to avoid significant delays in servicing aircraft. Currently, no online sensor exists to measure air content of hydraulic fluid. Air causes problems such as hotspots, cavitation in pumps, poor heat transfer, loss of power, decreased viscosity, foaming, and decreased flash point, which increase the risk of an explosion. Interspace has developed a prototype sensor that detects air in hydraulic fluids and has tested the sensor with MIL-PRF-83282, MIL-PRF-87257, and MIL-PRF-5606 hydraulic fluids used in military aircraft. This unique sensor noninvasively measures the percent air in hydraulic fluid. InterSpace proposes to build on its successful prototype sensor to extend the temperature range of operation for the target application.