摘要 |
According to the present invention, there is provided an optical sensor capable of detecting, identifying or measuring a property of a solid, liquid or gas which is in contact with its measuring surface. The preferred sensor comprises an optically transparent sensing element with at least one surface, anoptical energy source, means for conducting optical energy from the source to the sensing element at a specific, precisely determined angle and a photodetector. The measuring surface of the sensing element forms an interface with the substance to be measured. Optical energy is partially reflected from the interface formed at the planar surface of the transparent element toward the photodetector. It has been discovered that the resulting signal from the photodetector is proportional to the refractive index of the medium covering the outer surface of the transparent element 6.
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