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.
Micrometer scales, grids, circles and selected designs are suitable for use in the eyepieces of all microscopes for measurement, gauging, counting, comparison and absolute size determination. Three standard reticle diameters are available: 19mm, 21mm and 24mm. The desired diameter can be determined by accurately measuring the internal diameter of the eyepiece tube. Special sizes can be manufactured upon request. The reticles shown are not to scale. Allow 3-4 weeks for delivery.
When ordering: Please give catalog number 296 followed by pattern number and desired diameter. For example: 296-E29-19 is the designation for a 19mm diameter Whipple Grid. When ordering Walton/Beckett or IMA reticles please view the linked calibration sheet. Custom reticles available upon request.