: A transparent grid with equally spaced points is superimposed over a specimen image (micrograph or viewing screen). Points falling within the phase of interest are counted across multiple fields to achieve statistical significance. The Point Counting Procedure
: Samples must be sectioned and polished according to ASTM E3 to ensure a true two-dimensional representation. astm e56219 pdf
: Typically, 500 to 1,000 total grid points are evaluated to reach acceptable confidence levels. Statistical Formulas : A transparent grid with equally spaced points
The standard is the internationally recognized test method for Determining Volume Fraction by Systematic Manual Point Count . Grounded in the principles of stereology, it provides a statistical approach for estimating the volume of a specific phase or constituent within a solid material’s two-dimensional microstructural image. Core Purpose and Scope : Typically, 500 to 1,000 total grid points
: It applies to opaque materials where distinct phases can be identified, such as metals and alloys (e.g., ferrite in duplex stainless steel), ceramics , and composites .