Comparison of a 50 ml pycnometer and 500 ml flask

Project Description

The purpose of the comparison is to compare the results of the participating laboratories during calibration of 50 ml pycnometer and 500 ml volumetric flask using the gravimetric method.

Final Report 2016-05-12

The comparison has been completed and results are published in the KCDB

This EURAMET comparison, regarding the calibration of laboratory glassware instruments and pycnometers, started in February 2014 and ended in March 2015.
One 500 mL flask and two pycnometers of 50 mL were tested by 17 different laboratories.
Regarding the flask measurements there were four laboratories that had inconsistent results, this represents 23,5 % of the all results. After draft A was published the laboratories identified the causes of the inconsistencies and sent their corrected results with explanations. According to the CIPM rules its not possible to change results in draft A report so four explanations and En-values of the revised results for 500 mL flask were not considered officially in this report, but are included in Annex 3, for information purposes.
For the pycnometers measurements results are quite satisfactory. The majority of the laboratories present results that are consistent with the reference value, and with each other. There are two laboratories that present slightly discrepant values when compared with the reference value.
The uncertainty values presented for the pycnometers are quite similar for all laboratories. For the flask the situation is quite different and the uncertainty values presented can vary more than 3 times.