GB/T 40944-2021Determination of feed particle size—Geometric mean diameter method (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

1 Scope

This document specifies the geometric mean particle size determination method of feed particle size.

This document is applicable to the determination of the particle size of powder and granular feed materials, feed additives and feed products processed by crushing or other methods.

2 Normative references

The content of the following documents constitutes an indispensable clause of this document through normative references in the text. Among them, dated quotations Only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 5329 Test sieve and sieving test terminology

GB/T 6003.1 Technical requirements and inspection of test sieves Part 1: Metal wire woven mesh test sieves

GB/T 10647 Terminology of Feed Industry

GB/T 14699.1 Feed sampling

3 Terms and definitions

The following terms and definitions defined in GB/T 5329 and GB/T 10647 apply to this document.

4 Principle

Use the specified standard test sieve to screen the sample on the vibrating machine, determine the quality of the material retained on each layer of the sieve, and calculate the geometrical plane of the sample. Average particle size, etc.

5 Materials

5.1 Rubber ball or silica gel ball. 15mm~20mm in diameter, used to bounce to clean the screen and crush the fine powder agglomerates on the small aperture screen.