Two (ev. three) windmill-type anemometers of different size are measured by the participating laboratories and the results are compared. The measurement range is 0.5 to 40 m/s (ev. smaller, depending on the measurement possibilities of the participating laboratories. The instruments have a pulse output (TTL-level) and the meter factor (pulses per meter) is recorded for the different air velocities.
The instruments are measured at the beginning and at the end of the intercomparison by the Swiss laboratory. Eventually, after every three or four laboratories, the instruments are again measured by the Swiss laboratory to be certain, no significant changing has taken place. Transport by Post or parcel transportation enterprise.