Refractometer

Claim 1

In a refractometer for measuring the index of refraction of a sample medium, comprising a source of light; a sample medium sensor surrounded by a sample medium, a first light conductor coupling said sample medium sensor to the source of light so that the light from said source is directed along said sample medium sensor, said first light conductor having a substantially U-shaped curved unscreened portion which forms said sample medium sensor, first photodetection means connected to said first light conductor for measuring the transmitted radiant energy passed through said sample medium sensor; a reference medium sensor surrounded by a reference medium; a second light conductor coupling said reference medium sensor to said source of light; second photodetection means connected to said second light conductor for measuring the transmitted radiant energy passed through said reference medium sensor; test data processing means for measuring the difference in light transmitted by each sensor; and indicator means for indicating the index of refraction in accordance with said difference, the improvement comprising a single measuring probe, said sample medium sensor and said reference medium sensor being combined into said single measuring probe; a housing accommodating said source of light, said first and second photodetection means, said test data processing means and said indicator means; and cable means connecting said single probe to said housing, said probe including an elongated probe member, a casing surrounding said probe member, and a measuring tip having in the direction of elongation of the probe a substantially U-shaped cross-section and extended outwardly from said casing, said measuring tip having an outer surface carrying thereon said sample medium sensor, said measuring tip being formed with an internal hollow space filled with the reference medium, said reference medium sensor being positioned in said hollow space.