Sampling
Despite the precautions taken during sampling, an unavoidable error is introduced when the material being sampled has a heterogeneous composition. This error is known as the Fundamental Sampling Error (FSE) and can be quantified with the ECHANT software.
Many factors can interfere with sampling, such as systematic bias, nugget effects, size of the components sampled, type of sampling, etc. Therefore, a Sampling Plan or Flowsheet must be adapted to the specific characteristics of the batch and the units to be sampled. This flowsheet helps overcome the problem of distribution heterogeneity.
Monitoring the performance of any process relies on mass balances and recovery estimates, but these calculations are subject to uncertainty as a consequence of errors in the measured assays and mass flows.
One of the most important sampling rules is that there is a minimum sample mass required to achieve a given fundamental error at any stage of sampling. The sample mass cannot be reduced below this minimum until the sample is crushed to a smaller particle size.
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