Keywords: Sampling, Statistics, Specification, IBC, Fertiliser, Standards.
The important first steps in sampling are:
# To understand the fertiliser being sampled.
# To understand the specification for the fertiliser.
# To understand the needs of the analytical laboratory.
# To select the correct sampling device(s).
# To calculate the correct number of incremental samples.
All these are required before the samples are actually taken.
This paper describes the available methods for sampling fertilisers from manufacturing to delivery. It is shown that there are times where it is not possible to obtain a truly representative sample even when following the best guidance available in Standards, Regulations, and advice from experienced samplers. Current Standards and EC Regulation are discussed.
Some of the basic theoretical aspects required for an understanding of sampling are presented.
Problems with commercial specifications are discussed.
Some previously unpublished UK guidance on the sampling of IBCs (‘Big Bags’) is presented.
Practical examples are used wherever possible.
The majority of the paper deals with the sampling of solid fertilisers, with some discussion of sampling liquid fertilisers.
A decision tree for commercial sampling is provided.
David C Thompson, MA (Cantab), Consultant, Billingham, UK.
47 Pages, 7 Figures, 3 Tables, 32 References.