Self-test 4.4

Standard uncertainty is uncertainty expressed at roughly 68% confidence level

Standard uncertainty can be found, depending on situation, as standard deviation of parallel measurement results or standard deviation of the mean of parallel measurement results

Combined standard uncertainty can be calculated from expanded uncertainty by applying square root

Standard uncertainty is uncertainty that is found using a standard approach

Expanded uncertainty is found by adding the standard uncertainties of all input quantities

Expanded uncertainty is roughly equal to the measurement error

Expanded uncertainty expresses the range of values within which the true value lies with 100% probability

Combined standard uncertainty is standard uncertainty that has been calculated taking into account all relevant uncertainty sources

Combined standard uncertainty can be calculated from expanded uncertainty by dividing it with the coverage factor

Expanded uncertainty is uncertainty that has been found by taking into account more uncertainty sources than in the case of standard uncertainty

Expanded uncertainty is found by multiplying combined standard uncertainty with a coverage factor

Combined standard uncertainty is standard uncertainty expressed at roughly 95% confidence level

Expanded uncertainty is roughly equal to the measurement bias

132 mg/kg with expanded uncertainty 7 mg/kg, k=2. 

120 mg/kg with relative combined standard uncertainty 10%. 

125 mg/kg with relative expanded uncertainty 10%, k=2.

128 mg/kg with combined standard uncertainty 8 mg/kg. 

112 mg/kg with combined standard uncertainty 12 mg/kg.