Dipl.-Geoök. S. Müller
Dipl.-Phys. T. Ziems
Dipl.-Ing.(FH) R. Lieckfeldt
Accuracy in measurements and comparability of wind measurements require a specific calibration of the used anemometers. Anemometer calibrations by WIND-consult are carried out according to MEASNET respectively IEC 61400-12-1. WIND-consult has successfully participated since 2000 in the MEASNET round robin tests and is a MEASNET member in the field of anemometer calibration since June 2002.
Since October 2007 the WIND-consult GmbH is accredited for calibrations within the range flow measured variables by the accreditation body of the German calibration service, that was merged into the Deutsche Akkreditierungsstelle (DAkkS) since December 2009,
The calibration is carried out in the wind tunnel of the Institut für maritime Systeme und Meerestechnik of the Rostock University (see graphic below). The tunnel meets the requirements set by MEASNET regarding turbulence intensity, conformability of the flow and nozzle diameter (blockage ration). The wind tunnel is a closed tunnel with an open working section. The measuring diameter amounts to 1.400 mm x 1.400 mm.
Before and after each calibration in the wind tunnel comparing measurements with our reference anemometer are carried out.
The data collection is carried out with a measuring computer, a data card and the data logging and processing program DIAdem. Besides the collection of the flow velocity and the output signal of the anemometer, the external conditions for the correction of the measuring results at standard conditions are registered.
For the measuring data collection DAkkS-calibrated reference equipment respectively adjusted devices are used. The calculation of the characteristic line of the anemometer is carried out by a linear regression of the flow velocity and the output signal of the anemometer.
The preparation of the measuring results is summarized in a calibration report with the following details:
>> Regression coefficients, correlation coefficient, standard deviation and output signal at 10 m/s and 16 m/s, as well as
>> Detailed view on the uncertainty