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
Abraham Roentgen he established a furniture manufactory. Upon his retirement in 1772 his son David took over the business and established his own reputation. Abraham Roentgen died in Herrnhut in Saxony Germany in 1793. Abraham Roentgen Abraham Roentgen (30 January 1711 – 1 March 1793) was a German Ébéniste (cabinetmaker). Roentgen was born in Mülheim am Rhein, Germany. He learned cabinet making from his father. At age 20, he traveled to Den Haag, Rotterdam and Amsterdam, learning from established cabinet makers. He became known for his marquetry work, and worked in London (in the workshop of William Gomm) until 1738. On 18