This will seem like a simple question, but, should micro results on a COA be reported as an average of results, or the max. value found within the batch / section of batch received? I ask as I've seen both be used by different suppliers.
My own thought is that micro results on a batch COA should be the max. found, so that if a customer retests the product then they should find results either below or equal to those stated on the COA. If part of the product is found to exceed specification, then that can be separated into a different grade, and the max value of the remaining is valid for the initial grade.
E.g. if 100Mts of stock had results of 100, 300, 400, 600, 1000, and the spec was max 800. Then the stock covered by the first 4 results would go to grade 1, and the remaining volume goes to grade 2. The COA for the grade 1 product will report a max 600 result, and the Grade 2 will report 1000.
Plus, if average is used, its very easy to hide a spike in results.
If there are any guidance notes or text which refer to this that would be great to know.