NG52 Chalkley Point Array Pattern images provided for illustrative purposes only



Chalkley Point Array

Key features

Eyepiece Reticle with Chalkley Point pattern. A single Circle divided into quarters and populated with 25 points (dots).

Order code



£135.16 - £155.79

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This is used to quickly determine the relationship of components to each other using random sampling. An example of its application is given by Curtis, where a researcher might want to see whether or not a certain drug affects the volume proportion of cell types in a given organ. With this reticle the proportion of points lying over the image of one type of component is statistically proportional to the area occupied by that component. The 25 points of the array are placed over the field of view at random, so that a comparison can be made between the number of points touching the one type of component, with the number touching the other type of component in each viewing. A series of observations will yield an increasingly accurate ratio of the comparative incidence of each type of particle. Ref. A.S.C.Curtis. Medical and Biological Illustration, Vol. 10. pp 261- 266. “Area and Volume Measurements by Random Sampling Methods”


Glass Type and Thickness

Soda Lime 1.5mm thick

Diameter Tolerance



Correct reading through glass