Mechanical sampling bias testing

ASTM D-6518. Standard Practice for Bias Testing a Mechanical Coal Sampling System. 

ASTM D-6315. Standard Practice for Manual Sampling of Coal from Tops of Barges. ASTM D-6518. Standard Practice for Bias Testing a Mechanical Coal Sampling System. 

Sample preparation involves physical and chemical treatments which are potential sources of bias, variance, contamination, and mechanical loss. Sample preparation should be planned carefully and documented in sufficient detail to provide a complete record of the sample history. Furthermore, samples taken specifically to test the quality assurance system should be subjected to the same preparation steps as the test sample. 

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