CONVERSION SCALE Letter _Label Gamma Exposure Rate* (uR/h at 1 meter) A € 0.07 B 0 .07 - 0.14 C 0 14 - 0.30 D 0 30 - 0.65 E 0 .65 - 1.4 F 14 - 3.0 G 30 - 6.5 H 65 - 10 I 10 - 20 J 20 - 30 K 30 - 50 L 50 - 70 M 70 - 100 *Extrapolated from aerial data obtained at an altitude of 38 meters (125 feet). An additional 3.3 yR/h due to cosmic ray contributions must be added to obtain the total external exposure rate.