Automated Test Procedures
ASTM D6518 Coal Bias Testing
Bias testing of mechanical coal sampling systems is critical for ensuring that coal properties are accurately measured. Many companies often struggle with processing bias test data as specified by ASTM D6518.
DataWolff automates all three tests specified in this standard that include: the Student-t test; Hotelling’s T Squared test; and the Wilcoxon Signed Rank Non Parametric test. The automated data analyses create workbooks that indicate whether the system passed or failed, or whether the results were inconclusive. In addition time series of all data are automatically created. The plots below present ellipses for a Hotelling’s T Squared test that provide a clear interpretation of a test. Download the workbooks referenced by the links below to review example results from the ASTM D6518 analysis scripts.
Example Plots Created by the Hotelling’s T Squared Analysis
Click the image for a larger view
Test Ellipse Lies Within Ellipse Defined by Largest Tolerable Bias Values – No bias Detected in Measurement System
Test Ellipse Touches Ellipse Defined by Largest Tolerable Bias Values – Bias Test Is Inconclusive
Test Ellipse Lies Outside of Ellipse Defined by Largest Tolerable Bias Values – System Appears to Be Biased
Related Workbooks :
- StudentT.xls – Workbook created by the Student-t analysis script (160KB MS Excel format).
- HotellingTSquared.xls – Workbook created by the Hotelling’s T2 analysis script (320KB MS Excel format).
- Wilcoxon.xls – Workbook created by the Wilcoxon Signed Rank Non Parametric analysis script (644KB MS Excel format).
