If the first few counts show high variability, the standard provides formulas to determine how many additional fields must be counted to meet the required precision level. 4. Manual vs. Automated Image Analysis
While modern image analysis software (like ImageJ or proprietary systems) can perform "automatic thresholding," ASTM E562 remains the primary validation method. astm e562-19e1
The core of the standard is a simple but effective geometric probability technique. Instead of attempting to measure every grain or particle, an observer uses a transparent grid of points. Step-by-Step Procedure: If the first few counts show high variability,