ISO 13909-7:2016 Preview
Hard coal and coke -- Mechanical sampling -- Part 7: Methods for determining the precision of sampling, sample preparation and testing
In ISO 13909-7:2016, formulae are developed which link the variables that contribute to overall sampling precision. Methods are described for estimating overall precision and for deriving values for primary increment variance which can be used to modify the sampling scheme to change the precision. Methods for checking the variance of sample preparation and testing are also described.