Method and device for detecting a lubricating film on rails

摘要

The oil film detection system uses a laser (6) for directing a laser beam (5) onto the surface of the track rails, with respective detectors (12,13) for receiving the mirror reflected and diffuse reflected laser light. The signals from the detectors are fed to an evaluation stage (16) for evaluation of the individual signals, the sum signal and the signal ratio. Pref. amplitude modulation of the laser beam, or filters in front of the detectors are used for suppression of the background light.