Contents
MetPak RG User Manual
©
Gill Instruments Ltd
Last Change
Page 2
12 February, 2013
1.1
Principle of Operation
1.1.1
Wind Speed and Direction Sensor
The MetPak RG uses the WindSonic wind speed and direction sensor. The
WindSonic measures the times taken for an ultrasonic pulse of sound to travel from
the North transducer to the South transducer, and compares it with the time for a
pulse to travel from S to N transducer. Likewise times are compared between West
and East, and E and W transducer.
If, for example, a North wind is blowing, then the time taken for the pulse to travel
from N to S will be faster than from S to N, whereas the W to E, and E to W times
will be the same. The wind speed and direction can then be calculated from the
differences in the times of flight on each axis. This calculation is independent of
factors such as temperature.
Figure 2
Compass points
Figure 2 shows the compass point and polarity of U and V if the wind components
along the U and V axis are blowing in the direction of the respective arrows.
