The NG12 is particularly useful since the array of globes and circles are conveniently close to where the particles pass. At the end of each band of the sample the mechanical stage is traversed vertically to take in the next band until the whole sample has been covered. Reference: K.R.May, Journal of Scientific Instruments Vol. 42 1965. “A New Graticule for Particle Counting and Sizing.” Pp 500-501.

Glass Type and Thickness

Soda Lime 1.5mm thick

Diameter Tolerance

+0/-0.1mm

Orientation

Correct reading through glass