Determining Size of the Particles Leaving Domain

How to determine size of the particles that are leaving the domain?

In output control, create a particle histogram with and x variable=mean particle diameter, y variable=particle number rate, and sample location=outlet. This will write a CSV file representing a histogram showing the instantaneous particle number rate at the outlet for each particle diameter bin. To calculate the net particles leaving the domain over a transient simulation, manually (or using a script) parse through the collection of CSV files written each timestep.