This part of ISO 11929 specifies suitable statistical values which allow an assessment of the detection capabilities inhigh resolution gamma spectrometric ionizing radiation measurements, without the influence of sample treatment [1 to11]. For this purpose, statistical methods are used to specify the following two statistical values characterizing givenprobabilities of error.The decision threshold, which allows a decision to be made for each measurement with a given probability oferror as to whether the registered pulses in a region of interest of the spectrum include a contribution by thesample (e.g. a peak of a gamma line of a nuclide in question).The detection limit, which specifies the minimum sample contribution which can be detected with a givenprobability of error using the measuring procedure in question. This consequently allows a decision to be made asto whether a measuring method defined in this part of ISO 11929 satisfies certain requirements and isconsequently suitable for the given purpose of measurement.