There are at least 30 methods, of which 5 or more are applicable internationally. The remainder are national or regional standards. The need for sampling Batches of grain are rarely uniform in quality even when regarded as acceptable.
Pests usually occur non-randomly in stored grain.
Consequently the only sure way of obtaining complete and accurate information about the grain is to carry out a total examination. This may be possible if the quantity to be examined is small, but is usually neither practical nor economical when a large quantity is involved. The choice is either not to examine the consignment at all or to take samples to obtain some information, acknowledging that anything less than a total examination is bound to affect the accuracy of the results. Principles of representative sampling The results of sample analyses can be expressed in precise terms. However, precise analytical results may be of little practical value, and may be misleading if the samples are obtained without taking into account the non-random or aggregated distributions of foreign matter, damaged grains, insects, etc.