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
Dietrich Wilhelm Heinrich Busch Dietrich Wilhelm Heinrich Busch Dietrich Wilhelm Heinrich Busch (16 March 1788 – 15 March 1858) was a German obstetrician born in Marburg. In 1806 he earned his medical doctorate at the University of Marburg, becoming an associate professor of surgery in 1814. In 1817 he was appointed professor of obstetrics at Marburg, where from 1820 to 1829 he was director of the department of obstetrics. In 1829 he succeeded Adam Elias von Siebold (1775-1828) as professor and director of the obstetrics clinic at Friedrich Wilhelm University in Berlin, serving as university rector in 1835/36. He would remain as director of