Apparatus and method for detecting the presence of water on a remote surface

摘要

An apparatus is provided having a source for illuminating a remote surface with at least one wavelength of light (e.g., in the range of 940 to 970 nm), a detector for receiving returned illumination from the surface and providing an analog signal representative of the returned illumination, and a controller which samples the analog signal to obtain sample data representative of amplitude of light of the source returned from the surface by the detector. The controller determines the presence of water (or moisture, liquid, ice, vapor or heavy gases) on the surface in accordance with the sample data. An audible alarm is activatable by the controller. The source and detector are in a housing in perpendicular or non-perpendicular orientations with respect to the surface. Such housing being mountable at a distance from the surface where water detection is desired.

主权项

1. An apparatus for detecting a substance upon a surface comprising:
a source configured to illuminate a surface with at least one wavelength of light, wherein the source is configured to be driven at an oscillation frequency to modulate the illumination from the source; a receiver configured to receive returned illumination from the surface; a synchronous detector that provides a signal representative of the received returned illumination in accordance with the oscillation frequency that modulated the source; and a controller configured to sample the signal at a time in accordance with the oscillation frequency to minimize the effect of any ambient light received by the synchronous detector in the signal to obtain sample data representative of amplitude of light of the source returned from the surface, and the controller determines the presence of the substance, on the surface in accordance with the sample data.