Radon Graph of NBS SRM De-Emanation

This graph shows the results of de-emanating a National Bureau of Standards Radium solution into a 13.9 liter steel cylinder. We where fortunate to acquire a 13.2778 Bq National Bureau of Srandards SRM 4950 #29 back in 1986 before Radium was so strictly regulated. There is reasonably good agreement between this de-emanation and the de-emanation into the smaller cylinder.