- Bias are calculated with every sample coming from the XRF analyses and used to correct the online analysis so it is more “correct according to the XRF analysis”
- The XRF sample are considered to be the most correct sample.
- Formular used in QCX:
- New bias = old bias +(OLA corr - LAB ref)*Bias filter/100
- The online analysis shown in QCX sample viewer is always different from the original analysis because of the added Bias. This can be confusing
- If the BIAS is very large then there will be a large difference between the QCX analysis and the original analysis.
- The Bias is added like this:
- SiO2 bias = -0.02%;
original online data SiO2: 13% - Corrected data: 13 -(-0.02)= 13.02%
In the Bias calculation are used the Bias Filter values.
This is set in the configuration – see image- it is a % value set from 0-100%. If set to 100% then there is not filter and the Bias will fluctuate a lot because the calculations then are based on very uncertain measurements.
Default settings are 10%
Where to fine the Bias filter setting
Example from QCX sample Viewer showing the BIAS calculated from the XRF analysis.
These numbers are used for all online analyser results
until next XRF sample comes in. Then new BIAS are calculated and used for correction.
Example of BIAS trends in BLX