1.1 This guide covers general principles for obtaining a gross sample of coal by taking increments from part of a stream of coal rather than from the entire stream to be sampled. The usefulness of results from this guide will vary greatly depending on such factors as top size of the coal, size consistency of the coal, variability of the coal, and such logistical factors as the flow rate of the coal in process and physical accessibility of the sampling station.1.2 This guide should be u