Calibration is usually based on the ICUMSA tables,"ICUMSA Methods Book", op. cit.; Specification and Standard SPS-3 Refractometry and Tables – Official; Tables A-F but the user of an electronic refractometer should verify this.
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He noticed higher concentrations at the cooler end of the pipe. His experiments confirmed the results of C. Ludwig (published 20 years earlier) of which Soret probably did not know. In addition to thermal migration, he also conducted research on refractometry. In 1898 he became the rector of the University of Geneva.
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A refractometer is a laboratory or field device for the measurement of an index of refraction (refractometry). The index of refraction is calculated from Snell's law while for mixtures, the index of refraction can be calculated from the composition of the material using several mixing rules such as the Gladstone–Dale relation and Lorentz–Lorenz equation.
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Refractometers are frequently used by grape growers and kiwifruit growers for Brix testing of sucrose levels in their fruit. Refractometry is also used in the gelatin industry. To convert the RI of a gelatin sol (reported in Brix) to a gelatin concentration, one need only multiply by eight-tenths (0.8). A sol with a 10.0 RI would therefore be 8% gelatin by weight.
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In medicine, particularly optometry, ophthalmology and orthoptics, refraction (also known as refractometry) is a clinical test in which a phoropter may be used by the appropriate eye care professional to determine the eye's refractive error and the best corrective lenses to be prescribed. A series of test lenses in graded optical powers or focal lengths are presented to determine which provides the sharpest, clearest vision.
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These techniques can reveal how the short chain branches are distributed over the various molecular weights. A more efficient analysis of copolymer molecular mass and composition is possible using GPC combined with a triple-detection system comprising multi-angle light scattering, UV absorption and differential refractometry, if the copolymer is composed of two base polymers that provide different responses to UV and/or refractive index.
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Carl A. Vossberg, Jr., (born July 16, 1918 - March 9, 2008) was an American electrical engineer, inventor, and entrepreneur in the electronic instrumentation industry. He is known for more than 30 technical patents in the area of refractometry, measurement, and control. Vossberg also founded Electron-Machine Corporation, the company responsible for the introduction of inline process refractometers as a measuring system for the pulp & paper, food, and chemical processing industries.
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Refractometry is the analytical method of measuring substances' refractive index (one of their fundamental physical properties) in order to, for example, assess their composition or purity. A refractometer is the instrument used to measure refractive index ("RI"). Although refractometers are best known for measuring liquids, they are also used to measure gases and solids; such as glass and gemstones. The RI of a substance is strongly influenced by temperature and the wavelength of light used to measure it, therefore, care must be taken to control or compensate for temperature differences and wavelength.
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The International Commission for Uniform Methods of Sugar Analysis (ICUMSA) is an international standards body, founded in 1897,ICUMSA: History, retrieved 2010-02-07.. that publishes detailed laboratory procedures for the analysis of sugar. The ICUMSA Methods BookICUMSA Methods Book (2009), Verlag Dr. Albert Bartens KG, Berlin, 2010, and Supplement ) contains detailed instructions for analyzing raw, cane, white, beet, molasses, plantation white and specialty sugars. Among these are methods for determination of dry solids content by polarimetry, densimetry and refractometry, color (extinction coefficient at 420 nm), reducing sugars, and the presence of metals such as arsenic and copper. The Methods Book also contains polynomials and tables (derived from the polynomials)Methods Book, op. cit.
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Specification and Standard SPS-3 (2000) Refractometry and Tables which relate the refractive index of solutions of pure sucrose, glucose, fructose and invert sugar to the strength of those solutions. These are to be used with the analysis methods that characterize sugars by refractometric means but find wide application outside the sugar industry as the sucrose polynomial is built into the firmware of modern refractometers and is the basis for calibration of purely optical refractometers which read in Brix. Temperature correction factors, also derived from the polynomials, are the basis for the Automatic Temperature Compensation features found in those instruments.Reichert Analytical Instruments, AR200 Refractometer User's Guide Thus, a vintner measuring the Brix of juice from his grapes by means of a refractometer accepts a sugar content reading based on the refractive properties of sucrose despite the fact that the primary sugar in grape juice is fructose, not sucrose.
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