Estimation of measurement uncertainty in chemical analysis

Self-test 3.5

Here you can test whether you have correctly understood the concepts of rectangular and triangular distribution and where to apply these distributions.

1. The following data are given in in the certificate of a standard solution: C(HCl) = (0.10000 ±0.00010) mol/l. No additional information is given on the type of the uncertainty. Please convert the uncertainty to standard uncertainty assuming rectangular distribution and present the result with 2 significant digits.

2. The following data are given in in the certificate of a standard solution: C(HCl) = (0.10100 ±0.00010) mol/l. No additional information is given on the type of the uncertainty. Please convert the uncertainty to standard uncertainty assuming triangular distribution and present the result with 2 significant digits.

3. Which of the obtained uncertainty estimates is safer (i.e. lower danger to underestimate the uncertainty)?

rectangular distribution

triangular distribution