I am looking forward to measure Particle distribution (Size, Frequency) at the upstream of the oil separator in a vacuum pump. The oil mass concentration is believed to be higher at the upstream. Can I get an accurate challenge measurement if I use a Welas Particle counter or if I use any dilution system along with it, will that change the particle distribution? I would need this data in order to feed into Computational Fluid Dynamics simulation.

Thanks in advance.