Measurement of Liquid Concentration Based on White Light Interference of Michelson Interferometer

A method for accurately measuring the concentration of transparent liquids using white light interferometry based on Michelson interferometer is introduced. The principle of white light interference in measuring liquid concentration was explained. When white light is incident, if the reference and measurement optical paths have equal optical paths, colored stripes will be observed. The colored stripes are the benchmark of "zero optical path difference", and the readings of the colored stripes appearing in the upper and lower parts of the colorimetric dish are recorded, which is the displacement of the moving mirror. Taking NaCl solution and sucrose solution as examples, the relationship between solution concentration and moving mirror displacement was obtained, it can accurately measure solutions of unknown concentrations with an error of less than 1%.