Fig. 3.

Plot of measured activity concentrations of ¹³³Ba in epoxy for the “A” (2 mL), “B” (4 mL), and “C” (6 mL) cylinders series (a) and “D” (23 mL) series (b), as determined from the NIST Vinten 671 ionization chamber (VIC, dark bars) and the NIST HPGe detectors (light bars). The uncertainty bars correspond to a single (k = 1) uncertainty interval and were calculated as described in Secs. 3.2 and 3.3. Some source sets were sent to the comparison participants before they could be measured on the HPGE systems, therefore those values are not available.