Calculate the beta absorbed dose-rate of common pure beta emitters and a few beta-gamma emitters, given the activity and the
isotope. If the isotope and dose-rate are known, the activity may be calculated.
Two methods may be used, either fluence-rate equations or extrapolation tables from
the "Handbook of Health Physics and Radiological Health." In the latter method,
plane source for spills may be selected and backscatter factors are included in the calculation. Tritium (H-3) is included by request even though the energy and distance
traveled are extremely low. Sr-90 and Y-90 may be calculated
separately or in equilibrium together.