ASTM E562-19 outlines a standardized manual point-counting method for determining the volume fraction of constituent phases in materials using a 2D microstructure image, including specific rules for handling grid intersections. The technique ensures statistical precision through a 95% confidence interval and is commonly applied to determine the ferrite content in steels. Purchase the full standard or view redlines at the ASTM International website.
: Typically, 500 to 1,000 total grid points are evaluated to reach acceptable confidence levels. Statistical Formulas astm e56219 pdf
ASTM E562-19 standard outlines a systematic manual point-counting procedure for estimating the volume fraction of an identifiable constituent or phase within a material's microstructure. ASTM International Core Procedure Guide Sample Preparation Prepare polished metallographic specimens according to : Use light etching (e.g., shallow microetching per : Typically, 500 to 1,000 total grid points
Ensure magnification is set so that the constituent of interest is roughly half the size of the grid spacing. Counting Method Full Point (1) Counting Method Full Point (1) Many labs use
Many labs use E562-19 as the "ground truth" to validate their automated systems.