Moisture quantity detecting apparatus, has radiation source to emit radiation, and photoelectric converter to detect radiation reflected by measuring spot, where surface of spot is thermally conductive layer

摘要

The apparatus has a radiation source to emit radiation. A level controller (11) drives the source for an emission of a measuring beam. A photoelectric converter detects the radiation reflected by a measuring spot (5), where the reflected light varies according to scattered light or refractive index change due to moisture. An evaluation device compares the measuring signal with an electric reference signal to detect moisture. An active cooling component cools the spot. An independent claim is also included for a method for detecting a quantity of moisture on a measuring spot.