The calibrations are conducted by an accredited lab and based on their traceability to national standards (EN 17025) provide maximum accuracy. Per flow-ring (open fan and rings A-E or 1-4), the calibration includes testing three values each in the lower, mid-level and upper flow-rate measuring range in a chamber test stand at a pressure differential of 50 Pa. The manufacturer recommends the calibration of BlowerDoor fans every four years.
We recommend calibrating the BlowerDoor measuring fans at intervals of 4 years. The national regulations and the requirements of the applicable measurement standard must be observed.
We offer the calibration of measuring fans (with DAkkS-certificate if needed) monthly for all BlowerDoor fan models (BlowerDoor Standard model 4 and model 3, as well as BlowerDoor MiniFan model DuctBlaster).
Calibration is conducted once every month. Your binding registration for calibration must have been received by the 28th of the month preceding the calibration. Please use the form to register, thank you.
We calibrate all BlowerDoor measuring fans using a test stand designed and implemented by BlowerDoor GmbH, which has been calibrated by the Physikalisch-Technische Bundesanstalt (PTB), Germany’s national metrology institute, with an accuracy of ± 1%. This level of accuracy is necessary in order to attest conformity of the measuring fan of up to ± 4%. The calibration stand has been accredited by DAkkS (Deutsche Akkreditierungsstelle GmbH) in August 2017.
*Conformity indicates the accuracy of the measuring fan determined for the analysis of faults and errors stated by the calibration lab. This increases the validity of the calibration.
The structure of the set of five flow rings, with one aperture each, is particularly beneficial to the accuracy: The position of the pressure sensor as well as the geometry of the fan and the rings have been developed by experts in order to create a stable and reproducible velocity profile that, as far as possible, is independent from the counter pressure (building pressure differential). Serial tests have shown that, even after long use, BlowerDoor fans feature high measuring accuracy which clearly exceeds the minimum legal requirements. A previous fan check forms part of each fan calibration.