Scalar averaging - WMT700

WMT700 Series User Guide

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User guide

When you select scalar averaging, WMT700 calculates wind speed and direction averages by adding up each wind measurement from the averaging time and dividing the sum by the number of measurements. The time between each consecutive wind speed and wind direction measurement is 0.25 seconds.

Wind direction is a circular function with a discontinuity at North, where 360° is equal to 0°. For example:

359° + 5° = + 4°
0° - 5° = 355°

WMT700 translates wind direction to a linear function to determine the wind direction average. For example:

359° + 5° is translated to 364°, which is then further converted to +4° for output.

0° - 5° is translated to 355°.

This ensures that the wind direction average stays representative of the true situation even if individual samples occur on both sides of the zero direction.

If the data acquisition system requests data before the initial averaging time completes, the sensor returns the most recent complete measurement data.

The following figure shows an example of averaging wind direction when the measured wind values are 355° and 10°. The resulting average is 2.5°.

Figure 1. Example of wind direction averaging