
Total
ruled area: 7 X 7mm
For counting components of greatly varying densities in a specimen.
The frequency of the sparsely distributed particles in the major square
is related in the proportion 1:10 to that of the denser populations
counted only in the smaller square. 
A
squared reticle can be used for counting. Here the basic principle
is that a small area of the specimen is analyzed in order to obtain
information about the total area. This removes much irksome work and
is preferable in certain instances to analyzing the whole area. For
example when it is desired to compare the proportion of large to small
particles in a specimen, by using the Miller Disc, the smaller particles
may be counted only in the small square, the result being multiplied
by ten for comparison with the number of larger particles in the large
square. 
