Optimization of counting times for short-lived gamma-ray emitters in air filter samples.

A methodology for the optimization of the counting times in a series of measurements of gamma-ray emitters in air filters is presented. In the optimal measurement regime in measurements of all the filters in a batch, the same minimum detectable activity is attained. It is shown how the number of filters, the properties of the gamma-ray emitter and the equipment influence the measurement time of the batch of filters and the minimum detectable activity attained.