Laurent Polarimeter, Medical - Scientific Curiosity Device, Analysis The Laurent polarimeter, manufactured by DESCHAMPS, is composed of a long black-painted test tube resting on a metal axis supported by a cast iron tripod. Two elements are distinguished on each side of the tube. On the one hand, there is a reading disc called an analyzer with, in the center, an eyepiece equipped with its "zero" adjustment. Its control system is operated by means of a pinion. Perpendicular to this first arm, the alidade - this mobile ruler rotating around the vertical or horizontal axis of an instrument allowing angle measurement - carries a double vernier equipped with a magnifying glass, allowing a fine reading on the two graduated sectors. Above the central disc, there is the reading system for the divided circle. The limb has a graduation in angle degrees and a graduation in saccharimetric degrees (the two graduated sectors). On the other side of this long test tube is the polarizer, which consists of a lever for adjusting the angle of penumbra, influencing the desired light intensity. Between these two parts, a notch allows the polarimetric tube to be installed. Use: The Laurent polarimeter, manufactured by DESCHAMPS, and its polarimetric tube, allow the determination of the specific rotational power of different substances, the concentration of an optically active substance and the measurement of the sugar concentration of a solution (the polarimeter then becomes a saccharimeter). For these three uses, a light source - a sodium vapor lamp - is necessary. To determine the specific rotational power of a substance, a tube containing the substance to be analyzed must be inserted. The light beam passes through a Nicol prism. Half of the polarized light goes directly towards the solution, while the other half passes through a half-wave plate. These two beams, with different polarization angles, are analyzed through another Nicol prism. By rotating the analyzer, located on the eyepiece, the intensity of the two beams changes. Two angles are obtained in which the two halves are weakly or strongly illuminated with the same intensity. Two angles are then obtained and allow the optical rotation of the substance studied to be determined. To determine the concentration of an optically active substance, if the optical rotation of the substance studied is known, the procedure is the same. The concentration is then calculated by applying Biot's formula. To measure the sugar concentration of a solution, the experiment is identical. Only, the substance studied differs since it is a question of analyzing the sugar concentration of a solution. Condition: Used: An item that has been used. See the seller's description for more details... Used: An item that has been used. any imperfections. Period: 1900 - 1950 Type: Medicine Subtype: Instrument Country of manufacture: France Material: Metal