PHOTOELEKTRISCHE SCHALTVORRICHTUNG UND SCHALTVERFAHREN

摘要

A semiconductor light-emitting device (411a) emitting first light (L1) of a wavelength absorbed by a substance containing an OH group toward a detection object, a semiconductor light-emitting device (411b) emitting second light (L2) which is visible light toward the detection object, a photoreceptor (411c) receiving light from the detection object and acquiring first and second received light-quantities derived from the respective ones of the first and second light, and a processing system (S) correcting the first photoreceiving quantity on the basis of the second photoreceiving quantity are comprised. The processing system (S) determines the color of the detection object by the second photoreceiving quantity, and corrects the first photoreceiving quantity on the basis of this determination result. Further, it compares the corrected first photoreceiving quantity with a prescribed threshold value, detects whether or not water which is the subject containing the OH group is contained in the detection object, and outputs the same as an output signal (s1).