Bias Testing

Bias testing of a mechanical sampling system is the only way to determine if a sampling system is collecting a representative sample. ASTM advises that mechanical sampling systems should be tested initially and on a regular on-going basis for bias. Bias testing is statistically significant systematic error. Critical inspections are often used prior to testing to correct any problems that may cause bias.
Bias testing consists of a series of pairs of samples of the same coal. Usually a series of stopped belt reference samples and final save samples are collected and analyzed. The difference between analytical results is determined for each pair. The series of differences is subjected to statistical analysis to determine bias.
MAS provides a complete line of bias testing services, including critical inspections, collection, analysis and reporting of bias tests on all types of mechanical sampling systems.

Testing Standards Used By Miltech Analytical Services
Bias Testing of Mechanical Sampling Systems ASTM D6518
Inspection of Mechanical Sampling Systems ASTM D4702
Mechanical Auger Sampling ASTM D4916
Evaluation of On-Line Coal Analyzers ASTM D6543