6.2 Measure of Uncertainty

 Disclaimer

   Table of Contents...           

Measure of Uncertainty

An intercept table of Uncertainties is used to determine the measure of uncertainty for the analysis result. The values are shown throughout the system as +/- value after a result

Using the coarse example above, a pH result of 6.3 is reported as 6.3 +/- 0.25. Or from another example:

Calculate Precision from Uncertainties

If enabled, Bika calculates the precision required and round the results according to the uncertainties.

The rounding applies both for decimal results and results with scientific notation

The decimal position is given by the first number different from zero in the uncertainty, at that position the system will round up the uncertainty and results

For example

• a result of 5.243 and uncertainty of 0.22, the system  displays as 5.2 +- 0.2
• 13.5 and uncertainty 1.34, the system displays 13 +- 1
• 0.0077. uncertainty 0.0021, displays 0.008 +- 0.002

Enabled

Exponential Format Precision value 4

• If the Integer digits in the result > 4, the number is formatted in scientific notation
• If  it is < 4, it is formatted as decimal notation, rounded in accordance to the precision calculated from the uncertainty

 Disabled

If the Calculate precision from Uncertainties is disabled for the Analysis Service, the same rules described above applies, but the precision used for rounding the result is not calculated from the uncertainty

The fixed length precision is used instead

Manual Uncertainty input

Enabling this option, will allow Analysts to manually override system calculated defaults manually, often the case in more complex Analyses