The numbers I crank out for Effective Dose Equivalent constant from the current ANSI standard are: 0.030 Rem/hr/curie at 1 meter and 8.12E-6 mSv/hhr/MBq at one meter. from the simple uen/p calculation I get: 0.144 Rem/hr/curie at 1 meter. The "Handbook" carries dose constant for "Deep Dose Equivalent" i.e dose rate at 1 cm tissue depth. It lists: 4.98E-5 mSv/hr/MBq Dale Boyce dale@radpro.uchicago.edu