The capabilities of low airflow reproduction and the traceability

The study of low air velocities is accompanied by specific critical parameters, which are determined by flow generation, testing conditions and geometry, flow control tools and the means to determine these parameters. A comparison of the air velocity produced under different conditions represents a highly knowledge-intensive and detailed study. An inadequate evaluation of the data can lead to misuse of resources, inefficient handling of instruments, and a lack of optimal resource utilisation. To this end, the airflow development in the horizontally positioned measurement pipe of the standard Göttingen-type wind tunnel was compared with the flow in a measurement chamber of enlarged dimensions, to determine the effect of flow conditions on the readings of the velocity meters. The preliminary results have demonstrated the specific factors that hinder the accurate utilization of measuring devices at extremely low velocities and the factors that need to be incorporated to facilitate the correct interpretation of the readings.