Graticules for Stereology
The Mertz Graticules (36 point) - NGM1
Used to estimate the three dimensional surface areas of the surface density of a component in a given volume, when the component does not have a random orientation. It comprises a test system with parallel curved lines used for measuring the intersection of points.
Weibel 1 - NGW1
Weibel 2 - NGW2
Used when making a surface to volume ratio of a structure per mass unit. This graticule consists of a number of short lines with interruptions the same length as the lines. Basically, the number of intersections falling over the short lines are counted and the number of endpoints falling on the end of the structure are determined.
Reference: E.R.Weibel, Journal of Microscopy Vol. 95.pp373-378Current Capabilities and Limitation of Available Stereological Techniques, point counting method