Quotient of absorbed dose per unit of time, unit: Gy/h (Koelzer 2008, Borders 1991). The absorbed-dose rate is often specified in terms of its average value over longer time intervals, e.g. in units of Gy/min or Gy/h (ICRU). The absorbed dose in a material per incremental time interval, i.e. the absorbed-dose rate is the quotient of dD by dt. SI Unit = Gy•s-1 (ICRU) (ISO/ASTM 2004a).