The basic objective of sampling is to obtain a small portion (”spot” sample) for analysis that is truly representative of the material contained in a large bulk container, vessel, or pipeline shipment. Often, the spot sample may be as little as one part in greater than ten million. Frequently, a series of spot samples may be collected and composited for analysis, which can help to minimize randomness and nonhomogeneity and make for a somewhat more representative sample. Samples to be composited must be thoroughly mixed and volumetrically proportional.