High speed hot air leak sensor

摘要

A hot air leak sensor for sensing jet engine bleed air leaks in an aircraft. Infrared detectors are combined with thermal re-radiating elements which are installed in air passages adjacent to the bleed air ducts and downstream of the region where a bleed air leak may occur. The elements are approximately 50% transmissive and 50% absorptive to infrared radiation with wavelengths within the range of approximately 4 to 20 micrometers. Incident radiation within the field of view of the detector is both transmitted and absorbed for re-radiation to the detector. If no incident radiation within the sensor field of view is available, the re-radiating element still responds to the increased airstream temperature resulting from the bleed air leak and supplies radiation to the detector to provide detection of the leak.