EXACT AND APPROXIMATE METHODS FOR ANALYSIS OF TOTAL ERROR IN RADIATION MEASUREMENTS

Radiation measurement results are typically stated as an estimated act ivity concentration with an associated 95% error bound. Very frequentl y, however, the error bound cited at the ''95% confidence level'' is n othing more than counting error and, especially at higher levels of ac tivity, counting error may constitute a gross understatement of the to tal error that should reasonably be attributed to the measurement. Thi s paper compares the measurement confidence limits obtained using a ty pical approximate error propagation procedure with the ''exact'' confi dence limits. A Monte Carlo error propagation method is also considere d. The results of the three methods are compared using Rn-222 measurem ent procedures for illustrative purposes.