Roentgen (unit) absorbed dose in a wide range of matter. When measuring absorbed dose in a human due to external exposure, the SI unit the gray, or the related non-SI rad are used. From these can be developed the dose equivalents to consider biological effects from differing radiation types and target materials. These are equivalent dose, and effective dose for which the SI unit sievert or the non-SI rem are used. The following table shows radiation quantities in SI and non-SI units: Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays
Wilhelm Olivier Leube Wilhelm Olivier Leube Wilhelm Olivier Leube (14 September 1842 – 16 May 1922) was a German internist born in Ulm. He studied medicine in Tübingen, Zurich, Berlin and Munich, and from 1868 worked as an assistant at the medical clinic in Erlangen. In 1872, at the University of Jena, he became a professor of pathology and special therapy, as well as director of the medical clinic. At Jena, one of his assistants was noted physician Ottomar Rosenbach (1851–1907). Afterwards he was a professor at the Universities of Erlangen (1874–1885) and Würzburg, where in 1895/96 he served as university rector. Wilhelm