Roentgen (unit) this derivative quantity the roentgen equivalent physical (rep) to distinguish it from the ICR roentgen. The introduction of the roentgen measurement unit, which relied upon measuring the ionisation of air, replaced earlier less accurate practices that relied on timed exposure, film exposure, or fluorescence. This led the way to setting exposure limits,and the National Council on Radiation Protection and Measurements of the United States established the first formal dose limit in 1931 as 0.1 roentgen per day. The International X-ray and Radium Protection Committee, now known as the International Commission on Radiological Protection (ICRP) soon followed with a limit of
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