Degree Stoppani

The Stoppani degree was a common unit of relative density , named after the German instrument maker Franz Nikolaus Stoppani and his brother, which was mainly used in Germany to determine the alcohol content . The unit refers to the so-called vitriol - sulfuric acid - separating balance , which the Stoppani brothers constructed in Leipzig .

As early as 1795, the German chemist Jeremias Benjamin Richter had already made a hydrometer to determine the alcohol content, to which the Stoppani brothers referred, which is why Grad Stoppani and Grad Richter have the same numerical value.

The Stoppani and Richter scales are based on the percentages by weight and are often equated with these, although both scales have minor inaccuracies, for example 5 ° Stoppani / Richter = 4.99% by weight, this is because Richter and Stoppani did not use 100% pure alcohol when creating the scales.

Conversion of Richter-Stoppani degrees into relative densities

For liquids heavier than water (at 15.625 ° C): ${\ displaystyle d = {\ frac {166} {\ left ({166} - {\ text {° Stoppani}} \ right)}}}$

Lighter than water for liquids (at 15.625 ° C): ${\ displaystyle d = {\ frac {166} {\ left ({166} + {\ text {° Stoppani}} \ right)}}}$

literature

Associations to encourage the industrialist in Bohemia (ed.): Mittheilungen für Gewerbe und Handel Vol. 2 , Gottlieb Haase, Prague, p. 247.
August Schiebe (Ed.): Universal-Lexikon der Handelswissenschaften Vol. 6 , Fleischer & Schumann, Leipzig / Zwickau 1837, p. 26.
PH List & L. Hörhammer: General part. Active ingredient groups I , Springer, Berlin / Heidelberg 1967, p. 41
Brandes, Gmelin, Horner, Muncke and Pfaff: Johann Samuel Traugott Gehler's Physikalisches Worterbuch Vol. 1 , EB Schwickert, Leipzig 1825, p. 363.