Portable Fuel Leak Detector

摘要

Aerodyne Products Corp. successfully met the objective of this program, by the development of a device for measurement of fuel leaks in aircraft. This device satisfies the two requirements: (1) monitor enclosed bays for fuel leaks, and (2) measure the fuel leak rate after determining that a leak has occurred. The first application requires a rugged, reliable and inexpensive device that can be mounted in aircraft bays and; continuously monitor for fuel leaks. The second application uses the same device with a battery attachment for ease in handling by personnel to measure fuel leak rates. In this Phase I SBIR program, tests were performed with a breadboard spectral correlation device to determine detection sensitivity and to develop techniques for fuel leak measurements. The device determines the presence of fuel vapor in air by measuring the absorption of infrared radiation by the vapor. Air to be analyzed is drawn into an absorption cell. The device was calibrated with decane and can observe vapor down to 1 part per million. Fuels have the same infrared absorption band. Measurements were made of the leak rate from an aluminum sheet with a 6 mil pinhole. The measurement cycle started by first wiping the surface, then placing the air sampling tube above the leak and drawing air through the absorption cell. The vapor in the absorption cell increased with time due to liquid spreading over the surface. A steady peak level was reached when the diameter of the liquid layer became larger than the diameter of the sampling tube.