1.1 Confirm the performance of the instrument or the test procedure by analyzing a QC sample.
1.2 Prior to monitoring the measurement process, the user of the test method needs to determine the average value and control limits of the QC sample (see Practices D6299 and D6792 and MNL 7).
1.3 Record the QC results and analyze by control charts or other statistically equivalent techniques, to ascertain the statistical control status of the total testing process (see Practices D6299 and D6792 and MNL 7). Anyout-of-control data should trigger investigation for root cause(s).
1.4 In the absence of explicit requirements given in the test method, the frequency of QC testing is dependent on the criticality of the quality being measured, the demonstrated stability of the testing process, and customer requirements. Generally, a QC sample is analyzed each testing day with routine samples. The QC frequency should be increased if a large number of samples are routinely analyzed. However, when it is demonstrated that the testing is under statistical control, the QC testing frequency may be reduced. The QC sample precision should be checked against the ASTM method precision to ensure data quality.
1.5 It is recommended that, if possible, the type of QC sample that is regularly tested be representative of the material routinely analyzed.An ample supply of QC sample material should be available for the intended period of use, and must be homogenous and stable under the anticipated storage conditions. See Practice D6299 and D6792 and MNL 7 for further guidance on QC and Control Charting techniques.
