Standard international (SI) units which may be used in place of the roentgen, rem, and the rad are the coulomb per kilogram (C/kg), the sievert (Sv), and the gray (Gy). These units are related as follows:

1 coulomb/kilogram (C/kg) = 3,880 roentgens (R)

1 Sv = 100 rem

1 Gy = 100 rad

SI units must be used on transportation labels. Many radiation meters in use utilize R/hr for measuring dose rate. To convert R/hr to Sv/hr divide by 100. (For example: 60 R/hr ÷ 100 = .6 Sv/hr.)