BS 3406-1:1986

Foreword
Committees responsible
Guide
Section one. General
0. Introduction
1. Scope
2. Definitions
Section two. Collection of gross and laboratory samples
3. Guidelines
4. Sampling strategy
Section three. Selection of a sampling method for
subdivision of the laboratory sample
5. General
6. Homogeneity
7. Flow characteristics
8. Preliminary examination and precautions
9. Quantity of material to be sampled
10. Sampling efficiency
Section four. Methods for subdivision of the laboratory
sample
11. Scoop sampling
12. Coning and quartering
13. Chute riffling
14. Rotary sampling
Section five. Methods for the preparation of very small
test portions
15. General
16. Suspension sampling
17. Paste sampling
18. Sampling for microscopic analysis
Appendices
A. Comparative sampling efficiencies
B. Relationship between minimum sample mass and mass
     fraction of coarsest size
C. Bibliography
Tables
1. Relative efficiencies of sampling methods for free
     flowing powders
2. Powder sampling methods: variation of subsample
     masses
3. Relative efficiencies of powder sampling methods:
     subsample composition
4. Relative efficiencies of powder sampling methods:
     subsample mass
5. Comparison of sampling methods to obtain small
     test portions
Figures
1. Sampling strategies
2. Coning and quartering process
3. Chute riffler
4. Whole stream sampling
5. Whole stream rotary sample divider type 1
6. Whole stream rotary sample divider type 2
7. Divided stream sampling
8. Divided stream rotary sample divider
9. Suspension sampler
10. Minimum sample mass as function of mass-fraction of
     largest-size class in a well-mixed bulk material
     and required precision

Recommended methods for the subdivision of laboratory powder samples into test portions suitable for analysis by methods for the determination of the particle size distribution described in other Parts of this standard and for particle characterization analysis described in other British Standards.

This Part of BS 3406 provides guidance on powder sampling. It recommends methods for the subdivision of gross or laboratory powder samples into test portions suitable for analysis by methods for the determination of the particle size distribution described in other Parts of BS 3406 and for particle characterization analyses described in other British Standards. Ways of obtaining very small test portions are described.

This Part of BS 3406 indicates points to look for in a preliminary examination of the sample to assist in the selection of the most appropriate method to subdivide the powder in question. Factors affecting this selection are considered and recommendations made to ensure that the integrity of the sample is maintained throughout the subdivision process. Appendix A gives the results of investigations by several workers into the relative efficiencies of the sample dividing methods.

NOTE The titles of the publications referred to in this standard are listed on the inside back cover.