One is not found (involve) in colorimetric.. fule source

One is not found (involve) in colorimetric:
1- Cuvett
2- light source
3- Photo sensor and analyzer
4- fule source***
5- Filter.

A colorimetric dosage is a possible type of dosage when a chemical reaction gives colored products and if the intensity of the coloring is proportional to the concentration of the element to dose. The colorimetric dosages rely on the law of Beer-Lambert.

A colorimetric dosage is also possible using colorful indicators such as helianthine, phenolphthalein, bromocresol green which will color for example at different PH and therefore, will be able to indicate when you reach the equivalence point. We also talk about colorimetric titration.

Colorimetry, a science of color measurement, is a metrological discipline that is part of the field of applied physical sciences. Since 1980, the development of easy -to -use measurements - colorimeters and spectrocolorimeters - has made it possible to obtain reliable measurements that have replaced subjective color comparison methods.

Color reproduction is not a new question in the history of human activities. The first colorful textiles, found in graves of Egyptian pharaohs, were dated about 2,500 years before our era. The manufacture of colorful fibers or textiles has long been the fruit of carefully kept knowledge. The accuracy of color reproduction was then only evaluated by visual comparison, the human eye being a very good "comparator". Also, for centuries, reference samples have been used to obtain the desired colors. This technique has particularly developed and perfected in the fields of paint and dyeing textiles. Catalogs, samplers or colors are always used (decoration, automobile, etc.). However, they remain limited to subjective comparisons insofar as their organization is independent of the fundamental parameters of color perception. Recall that the characterization of a color involves the definition of its three main psychophysiological attributes: shade, saturation and brightness or clarity (see color).

More rational than catalogs, the “color atlas” offer a classification and an organization according to the basic attributes of the color. The first known is the one who was developed, in 1864, by the Frenchman Michel Eugène Chevreul (1786-1889). In 1905, the American Albert Henry Munsell (1858-1918) created a perfected atlas where the three attributes of color were strictly represented according to incrementations corresponding to the response of the human eye. This atlas remains used in an optimized form.

In the 20th century, physicists of the International Lighting Commission (C.I.E.), founded in 1931, developed, this same year, a colorimetric system from three virtual primaries (x, y and z) allowing to define mathematically attributes of all real world colors (cf. color).

This system, built with a scientific purpose, quickly found itself confronted with the pragmatic necessities of human activities where the faithful reproduction of colors has become an essential issue. Research was then oriented towards a quantification of the differences between colors, in accordance with that perceived by the human eye. These studies were also intended to determine the differences in values ​​within which the eye does not discern a color difference.

This quest for the perfect "psychometric" tool is not yet completed despite the successive improvements obtained both by theoretical work and the sophistication of colorimetric measurement devices. Nevertheless, modern colorimetry has become an essential component in most artistic, industrial and agrifood activities.