Determine uncertainty of collection of data

[Mariob]

Hello, I work in a liquid calibration Lab and we are applying for ISO 17025. Basically we verify customers flow meters against our standard and capture the data onto our calibration report. An example is I would perform 4 tests of a specific flow rate and calculate the error in % for each test. Ex: test1 = .12%, test2 = .08%, test3 = .14% and test4 = .09%. How would I determine the uncertainty based on the given data.

 

[brainpushups]

You could use the standard error (standard deviation of the mean) which is the 'standard' way of reporting statistical error. However, with only four pieces of data you will have an uncertainty in your uncertainty of roughly 40%. If you are unfamiliar with standard error there are plenty of resources online to help which a google search will turn up.