Gill Instruments Ltd
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MetPak/MetPak RG and MetPak Pro Base Stations
Page | 7
Issue 1
Doc. No. 1723-PS-0023
October 2018
2.1.3.
Wind Speed and Direction Sensors
The MetPak Range Base Stations can be used with Gill 2 axis (WindSonic or WindObserver) or 3
axis (WindMaster or WindMaster Pro) wind speed and direction sensors. They are connected via
the supplied MetPak Hub Box RS422 communication and power 10 Metre cable.
MetPak Base Station Wind Sensors measure the times taken for an ultrasonic pulse of sound to
travel from the North (N) transducer to the South (S) transducer, and compares it with the time for
a pulse to travel from S to N transducer. Likewise times are compared between West (W) and East
(E), 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.
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.
Wind Sensor Base Station units output Relative wind – wind speed and/or direction relative to the
north marker.
WindSonic Range North Marker and UV Wind Components
WindObserver Range North Marker and UV Wind Components
Align the WindObserver using the North Transducer Arm.
