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The representativeness of sampling has already been explained in Chapter 3.2, Part II and it has been shown that representative sampling sometimes is difficult to evaluate and sometimes hard to achieve.

Figure II.19: Aliquot of a coating sample separating into three phases upon storage

Figure II.19 shows an aliquot of a coating material sampled from a hobbock. Upon storage this material separates into three layers. So, the challenge is to draw a representative sample from the hobbock which can be achieved most closely by stirring before sampling. Taking a random sample from the top or the bottom without stirring thoroughly will most likely result in non-representative aliquot sampling. In addition to that aliquots of different container areas should be taken and combined to one laboratory sample.