valve is type 562416 manufactured by elcam valve v 6 may be a three position valve providing two directions of flow and an u201c off u201d position as noted above controller 180 controls the operation of valves v 1 v 2 v 3 v 4 v 5 and v 6 ionization chamber 130 and scale 140 in one embodiment controller 180 may be a microprocessor driven controller for example a plc such as b amp r series 2003 manufactured by b amp r industrieelektronik austria may be used in another embodiment at least some of valves v 1 v 2 v 3 v 4 vs and v 6 may be manually controlled referring to fig2 a method for measurement of radioactivity concentration and total radioactivity of a radiopharmaceutical is disclosed although the method depicted in fig2 will be described in the context of the system of fig1 it should be recognized that the method is not limited to use with such a system in step 210 initial measurements are made in one embodiment the weight of bulk vial 120 without the tracer solutions is determined the background radiation level may also be measured in order to determine a radiation base noise level in step 220.