The purpose of the Standard is to define a test and analysis procedure to determine the particle dimensions and particle size distribution (PSD) based on particle length for chopped forage, ground biomass, or other particulate materials using the machine vision method. The developed methodology (i) uses an image of the particulate material, obtained using a document digital scanner or digital camera, processes through an image processing system (Fiji/ImageJ) to measure basic particles’ dimensions, and (ii) derive other properties, calculate their geometrical volume (in lieu of particles mass), analyses the PSD with a statistical computing programming language (R), and outputs results in textual and graphical forms.

Various size parameters (e.g., minimum, maximum, mean, standard deviation (STD) of length, width, aspect ratio, cumulative undersize dimensions, etc.), area and volume (total, minimum, maximum, and mean) as well as PSD parameters (e.g., uniformity index, size range variation coefficient, relative span, coefficient of uniformity, etc.) of particulate samples are determined.

The determined PSD results can be used to evaluate forage and biomass harvesting and processing equipment variables and to define the chopped forage length, fineness of ground biomass, and counting of sample particles. The procedure will work both for fresh (forage) and dried particulate material. The procedure can be readily extended to other particulate materials such as food grains, feed, minerals, or any granular free-flowing material.

This Standard is based on and compatible with ANSI/ASAE S319.4 and S424.1 and related ISO standards.