For the three largest sizes the estimated number of particles to be inspected lies between 217 and 312. For all smaller sizes the number varies (with size) from 1852 to 2945. These numbers are based on my own Excel-based model.
The biggest problem with AMS 2431 shape analysis is that it is based on subjective visual inspection - different people will give different answers for the same samples. It would be very useful if a set of reference images could be produced. These only require a digital photograph to be produced for each of the field being viewed. These images could be displayed on any computer screen to be 'visually inspected'. Assessments by different individuals could then be compared. This could lead to a future insistence on computer-based image analysis!
