American Roentgen Ray Society American Roentgen Ray Society The American Roentgen Ray Society (ARRS) is a radiology society in the United States. It was founded in 1900, in the early days of X-ray and radiation study. Headquartered in Leesburg, Virginia, the society publishes a monthly peer-reviewed journal: "American Journal of Roentgenology" (previously "American Journal of Radiology"), providing a forum for advances in radiology and related fields. It provides scholarships, and presents awards. Its educational programs include seminars and a program of continuing education for radiologic technologists. Its 9th meeting, in 1908, was held in New York City. There, it announced that there was "no
Roentgen (unit) of temperature and pressure." Using 1 esu ≈ 3.33564 C and the air density of ~1.293 kg/m³ at 0 °C and 101 kPa, this converts to 2.58 × 10 C/kg, which is the modern value given by NIST. 1 × 3.33564 × 10 × 1,000,000 ÷ 1.293 = 2.58 × 10 This definition was used under different names (e, R, and German unit of radiation) for the next 20 years. In the meantime, the French Roentgen was given a different definition which amounted to 0.444 German R. In 1928, the International Congress of Radiology (ICR) defined the roentgen as "the