The ALGE-TIMING anemometer WS2 works with calorimetric mass flow sensor. This allows a fast and precise air speed measurement and shows an exceptional dynamic. The optimal design of the sensor and the rapid reaction time for a measurement prevent wind changes between the measurements and permit measurements below 1 m/s. The WS2 does not need any recalibration as no mechanical parts are used. The elements keep their characteristics during the whole operation period. Interfering factors by humidity or temperature are non-existing.