Standard Guide for Part-Stream Sampling of Coal

Abstract

5.1 This guide provides instructions for Condition C sampling by collecting individual increments from part of a cross section of a moving stream of coal, as opposed to collection of individual increments by removal of a full cross section of material. The use of part-stream sampling, and the detailed procedures for each case, should be agreed upon in advance by all parties concerned. Samples collected by use of this guide are not probability samples. The user is cautioned that samples of this type do not satisfy the minimum requirements for probability sampling and as such cannot be used to obtain any meaningful statistical inferences such as the sampling precision, standard error, or bias. 5.2 All parties should be cautioned that manual or mechanical part-stream sampling of coal from a moving stream might not enable sampling of the material that is furthermost from the point of entry into stream by the sampling device. 5.2.1 Mechanical part-stream sampling is Type I sampling (see Practice D2234/D2234M) where no human discretion in the location of the collection of increments is employed. Type I selection increments generally yield more accurate results. 5.2.2 Manual part-stream sampling is Type II sampling (see Practice D2234/D2234M) where some measure of human discretion in the location of the collection of increments is employed.