Fibre-optic liquid refractive index measuring device (refractometer)

摘要

The measuring device for determining the refractive index of liquids consists of a first optical fibre assigned to a light source and a second optical fibre, which is assigned to a detector. Both optical fibres are connected via a fibre coupler to a third optical fibre whose ground and polished end represents the sensor. More or less light, which reaches the end via the optical fibre, the coupler and the optical fibre, is retroreflective to the detector as a function of the refractive index of the liquid surrounding the end.