Logo of the Physikalisch-Technische Bundesanstalt

11. Flow Measurands

Peter Reinshaus

The Technical Committee “Flow Measurands” was founded in March 2007 and is thus one of the youngest DKD Technical Committees. It represents about 25 accredited calibration laboratories for the measurands “flowrates of gases and liquids” and “flow velocity”. The Technical Committee‘s activities focus on: • the realization of interlaboratory comparisons among the member laboratories • the information of its members about new developments/trends in the fields of calibration (provided by employees of the PTB) and accreditation (provided by the responsible representatives of the the DAkkS) • the development of calibration guidelines as a basis for identical approaches and the comparability of calibration results 

In line with the areas of expertise, three working groups were formed, each dealing with one of the three specific topics. Currently, the Technical Committee is conducting an interlaboratory comparison for flow calibrations with the medium water at room temperature.

To this end, general rules for the realization as well as a table containing the possible measuring ranges of the participants have been set up. The PTB has assumed the role of pilot laboratory and will also support the evaluation. The necessary transfer standards were either made available by the participants or were jointly purchased. The latter are to be kept at PTB for future similar comparisons after the completion of the measurements. In addition, the Working Group “Flow Velocity“ has dealt with the comparability of calibration conditions for the calibration of anemometers.  

The basis for this was provided by a comparison measurement carried out among the respective calibration laboratories. Moreover, work is being done to create a guideline for the measurement of thermal energy. The international comparability of accreditations regarding technical aspects is another point that requires harmonization and should be improved in cooperation with the DAkkS and PTB.