» Leytz colorimeter with two trays (0253)

Immagini

DESCRIPTION

Exhibit 253 is a Leitz colorimeter designed to determine the absorption of one substance by comparing it with a known substance. The colorimeter furnished two test tubes and observation columns; one for a known concentration of the known substance and one for the concentration of the unknown substance. In practice two light beams coming from the same source are directed through the two tubes and the operator compares the intensity of the two emerging beams ^[1]. To facilitate the comparison, the colorimeter allowed varying the thickness (height) of each column of substance until the two intensities were equal, since the response of the human eye is only logarithmic. The two transmitted light beams are brought together by two prisms to illuminate the diaphragm D in figure 1. When both halves of the diaphragm are equally illuminated we have: concentration (1)*height(1)=concentration (2)*height(2) and can now determine the concentration (2) where the concentration (1) is known.

ISCRIZIONI

Inciso sullo strumento: " Ernst Leitz ¶
Wetzlar"

BIBLIOGRAPHY

[1] E. Perucca,"FISICA, Generale E Sperimentale", IV ed., UTET 1942

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