Roentgen (unit) Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays. It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air. In 1928 it was the first international measurement quantity for ionising radiation to be defined for radiation protection, and was an easily replicated method of measuring air ionization directly by using an ion chamber. It is named after the German physicist Wilhelm Röntgen, who discovered X-rays. Although relatively easy to measure, it had
Wilhelm Krause Wilhelm Krause Johann Friedrich Wilhelm Krause (July 12, 1833 – February 4, 1910) was a German anatomist born in Hanover. He was the son of anatomist Karl Friedrich Theodor Krause (1797-1868). In 1854 he earned his medical doctorate, and later (1860) became an associate professor at the University of Göttingen. In 1892 he was appointed head of the Anatomical Institute Laboratory in Berlin. Krause is known for the discovery and description of mechanoreceptors that were to become known as "Krause's corpuscles", sometimes referred to as "Krause's end-bulbs". His name is also associated with: Krause is also remembered for pioneer research