Table 8.

Results of the isotope dilution analysis by α-particle spectrometry using a ²³²U tracer (SRM 4324B). The measurement values are based on twelve determinations of ²³⁴U and ²³⁸U obtained from four replicate counting sources in two geometries (eight spectra), where four spectra were independently analyzed by two independent spectral analysis procedures. The certified massic activities for SRM 4321d are taken from Table 2. Numbers in parentheses represent the numerical values of the expanded uncertainties (for k = 2) and refer to the corresponding last digits of the quoted result. The uncertainty components that comprise the standard uncertainty for the measured values are given in Table 9.

	Massic activity (Bq g−1)
	A234U	A238U
Measured value	219.9 (2.7)	229.5 (2.9)
Certified value for SRM 4321d	220.2 (1.1)	228.93 (57)
Relative difference	−0.12 %	+0.25 %