Range of application

Due to its very short measurement intervals, the instrument is ideal for the inertia free measurement of gusts and peak values. The accuracy of the air temperature measurement (virtual temperature) surpasses that one of the classic method where the temperature transmitter is used in a weather and thermal radiation shield. The measured data are available as analogue signals or as a data telegram over a serial interface. The anemometer is equipped with an automatic heating for the instrument body as well as for the sensors so that the measuring results, in case of critical ambient temperatures, are not affected by ice, snow or rainfall.

Mode of operation

The Ultrasonic Anemometer 2D consists of 4 ultrasonic transformers, in pairs of 2 which are opposite each other at a distance of 200 mm. The two measurement paths thus formed are vertical to each other. The transformers act both as acoustic transmitters and acoustic receivers. The respective measurement paths and their measurement direction are selected  via  the  electronic  control.  When  a measurement starts, a sequence of 4 individual measurements is performed in all 4 directions of the measurement paths at maximum speed. The measurement directions (acoustic propagation directions) rotate clockwise, first from south to north, then from west to east, from north to south and finally from east to west. The mean values are formed from the 4 individual measurements of the path directions and used for further calculations. The time required for a measuring sequence is approx. 2.5 msec at +20 °C at the maximum measuring speed.