Getting a feeling of what is measured and how it is measured is a good property of measurement equipment. The particle deposition measurement equipent provides a transparent chain of data that can be verified by remeasuments or using particles of known size. Even NIST particles are available for testing the size accuracy. Counting is not complicated as all particles are shown in the viewer and last but not least a microscope can be used to check every single particle. As a measurement does not disturb the original the witness plate can be stored for evidence. It is a truely transparent system.