The ultrasonic measurement principle allows, compared to the classic anemometers, an inertia-free measurement of running variable dimensions with highest precision and accuracy. It is especially suitable for the measurement of gust- and peak values. The measurement values can be transmitted digitally and/or in analogue form. The serial or analogue output of the data is carried out alternatively as instantaneous value or with selectable time frame. If necessary, the sensor arms are automatically heated in case of critical ambient emperatures. The possibility of malfunction, caused by icing, is minimized. Model no. 4.3820.3x.xxx, thanks to the additionally installed ultrasonic converter heating, is suitable even for the more difficult use in locations where frequently icing is to be expected