Degree Tralles

The degree Tralles , named after the German physicist Johann Georg Tralles , was a unit of relative density commonly used in Germany and was mostly used to determine the alcohol content . It is derived from the hydrometers of the same name, invented by Tralles in Leipzig in 1812 .

The degree Tralles largely corresponds to the volume percent or is almost identical to the unit degree Gay-Lussac (° GL) used in France , so corresponds to:

1 ° GL = 1.03 ° Tralles ≈ 1% by volume.

The slight differences result from the fact that both used different reference temperatures, Gay-Lussac carried out his measurements at 15 ° C, Tralles at 15.56 ° C and today the volume percentage is determined at 20 ° C.

source

• Notices from the Imperial Standard Calibration Commission, Springer Verlag, Berlin 1912, p. 119