Mean constant of high performance gas chromatograph fixative

The Roche constant of the high performance gas chromatograph fixative is based on benzene, ethanol, methyl ethyl ketone, nitromethane and pyridine as the standard materials. They are determined at 100 ° C column temperature between the fixed solution and squalane to be tested. The difference ΔI of the index is retained and divided by 100 to obtain the characteristic constant of the fixed solution to be tested.
After studying the Roche constant and its determination method, McReynolds proposed an improvement scheme in 1970, using benzene, n-butanol, 2-pentanone, 1-nitropropane, pyridine, 2-methyl-2-pentanol, 10 kinds of substances such as iodine butane, 2-octyne, dioxane and cis-octahydroquinone were used as standard materials, and their ΔI values ​​between the fixed solution and squalane were measured at 120 ° C. The characteristic constants of the fixed liquid to be tested are represented by X', Y', Z', U', S', H, J, K, L and M, respectively, and are called the McMaster's constant.
McReynolds measured the Michael's constant of 226 fixatives. After induction, it was found that the first five substances were sufficient to express the relative polarity of the fixative, and the sum of the five terms was called the total polarity. The greater the total polarity, the stronger the polarity of the fixative.
The Roche constant is measured at a column temperature of 100 ° C, and the Beer's constant is measured at a column temperature of 120 ° C, and the structures of the standard materials used are different. The numerical relationship between the Roche constant and the Beer's constant is approximately: the Michaelson constant = the Rogowski constant × 100.

Plano Concave and Bi-Convex/concave Cylindrical Lens

Plano-concave Cylindrical Lens is an optical product, which is a divergent linear virtual image used to control the size of the light beam in only one direction. Combined with a plano-convex cylindrical lens, it can be used to shape the elliptical beam of a semiconductor laser into a circular beam. Plano-concave cylindrical mirrors can be used in projection systems, imaging systems, optical instruments, and laser measurement systems. Plano-concave cylindrical mirrors are also commonly used to convert a collimated laser source into a line light source, and plano-concave cylindrical mirrors are often used for beam expansion applications. Compared with spherical lenses, cylindrical lenses are more difficult to manufacture.Cylindrical lens is mainly used to change the design requirements of imaging size. For example, convert a point spot into a line spot, or change the height of the image without changing the desired width. The special optical performance of cylindrical mirrors. With the rapid development of high technology, cylindrical mirrors have become more and more widely used.

Concave Cylinder Lens,Cylinder Lens Concave,Convex Cylindrical Lens,Cylinder Rod Lenses

Bohr Optics Co.,Ltd , https://www.bohr-optics.com