Richard Assmann

In 1885 he earned a doctorate in secondary studies at the Faculty of Philosophy at the University of Halle, and subsequently became a scientific officer at the Royal Meteorological Institute at Berlin-Grünau.

From 1887 to 1892, with airship designer Rudolf Hans Bartsch von Sigsfeld (1861–1902), he developed a psychrometer for accurate measurement of atmospheric humidity and temperature.

This was the first instrument that was able to provide reliable temperature readings with high altitude balloons, as it was capable of shielding its thermometric elements from solar radiation.

From 1888 to 1899, he was a member of the Verein zur Förderung der Luftschifffahrt, from which he organized scientific balloon ascents in order to study the atmosphere.

[1] With Léon Teisserenc de Bort (1855–1913), he is credited as co-discoverer of the stratosphere, as both men announced their discovery during the same time period in 1902.

Threefold aspiration-psychrometer (Assmann type, prior to 1900)