Optical Interferometric Bench Salinometer of High Precision with Electrical Read Out

A Michelson type interferometer has been realized for high precision refractive index measurements of liquids, especially for sea water analysis. Main features are two 4 cm long thermostated optical cuvettes for taking up the liquids under test, standard sea water or distilled water as reference liquid, respectively, and an automatically controlled continuously mixing valve. The latter enables the use of a simple electronical fringe counting technique with a reasonable resolution of 1/100 fringe, allowing e.g. for salinity determinations with a precision of less than .