Uncertainty Components Evaluated for Determination of Total Activity Contained in NIST-Prepared 68Ge Epoxy–Filled Syringes

Component, uiCommentMagnitude (%)
SSIC chamber calibration factorCombined standard uncertainty on activity of solution-filled sources used to derive calibration factor0.47
Current measurement repeatabilitySD of mean on 10 measurements of current for single source0.21
Background variabilitySD of mean on 1,000 measurements of background current for single source2.00E−02
Decay correctionStandard uncertainty in half-life (0.059%) over measurement decay interval2.40E−03
Current measurement reproducibilitySD on 2 measurements of each source; typical value0.04
Combined (uc = √Σui2)0.52