Factor of merit and minimum detectable activity for 90Sr determinations by gas-flow proportional counting or Cherenkov counting

The determination of 90Sr in environmental samples can be done by using a gas-flow proportional counter (β-counting) or a liquid-scintillation spectrometer (Cherenkov counting). In this work, we present the factor of merit (FOM) and the minimum detectable activity (MDA) for both the counters. Quantitative relationships are proposed for FOM and MDA determination.