Table 1.

Calculated activities and characteristic limits for a separate evaluation and different combined evaluations of the 2 alpha-spectrometry measurements with which the correctness of the method was tested. Without a combination of emissions, the presented activity is the arithmetic mean of the activities of the 3 emissions, the uncertainty is that of this mean and the decision threshold and detection limit is the minimum of those of the single emissions as it was reported by Genie 2000. All uncertainties are presented with a coverage factor k = 2

Method	Spectrum	Activity (Bq)	Uncertainty (Bq)	Decision threshold (Bq)	Detection limit (Bq)
Separate evaluation	A	91	18	0.84	4.8
	B	98	15	0.28	1.6
Method a: Combination of emissions	A	93	24	0.48	2.0
	B	97	21	0.092	0.52
Method b: Combination of spectra	A + B	93	15	0.74	3.0
Method a & b: Combination of emissions and spectra	A + B	99	23	0.30	1.1