Tracking the mass that falls onto the BE sphere

I would like to calculate the mass that falls onto a BE sphere from the ambient over the course of a simulation. There may be a few ways to do this, but easiest may be what came to mind today: find M(t) using Visit's query option for total mass in box.

The method

First, I had to determine the right sum to use in visit. I see that the 'query' option had 2 sums: weighted and not. Additionally, the sum query is for the current plot. If that plot is a slice of the full simulation, the query will return only a sum of variables from that slice's mesh.