International Commission on Radiological Protection
Conversion coefficients from air kerma in Gy to equivalent dose in Sv are published in the International Commission on Radiological Protection (ICRP) report 74 (1996). For instance, air kerma rate is converted to tissue equivalent dose using a factor of Sv/Gy (air) = 1.21 for Cs 137 at 0.662 MeV.