Placing WMT700 - WMT700

WMT700 Series User Guide

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User guide

Install WMT700 on one of the following:

  • Side of the mast
  • Top of the mast
  • Support arm
CAUTION When selecting the mounting position and routing the cable, take into account the other equipment installed on the mast (for instance, air terminals).
When you are installing the sensor, pay attention to the North arrow printed on top of the sensor. The North arm is marked with an orange sticker.

Finding a suitable site for WMT700 is important for getting representative ambient measurements. Select a site that represents the general area of interest. Follow the WMO Guide to Meteorological Instruments and Methods of Observation WMO-No. 8, or other application-specific requirements set by various organizations, like the International Civil Aviation Organization (ICAO).

It is important to take into account the geography and surrounding area to achieve optimum performance. Trees, buildings, or other objects near WMT700 disturb free air flow and affect the accuracy of the measurement results.

Vaisala recommends installing WMT700 higher than any other object within a horizontal radius of 300 m. In general, any object of height (h) does not remarkably disturb wind measurement at a minimum distance of 10 × h.

When mounting WMT700 on top of a building, the recommended minimum height (h) for the mast is 1.5 × the height of the building (H). When the diagonal (W) is less than the height (H), the minimum height of the mast is 1.5 × W.

Figure 1. Recommended mast length on top of building
Recommended minimum height for the vertical mast
Height of the building
Diagonal of the building

When there is a need to ensure free air flow with a cross arm installation, the distance (y) between WMT700 and the mast must be more than 20 × the diameter of the vertical mast (z). See the following figure and follow application-specific installation guidelines.

Figure 2. Recommended location in open area
Height of a building or other high structure
Distance from a building or other high structure
Distance from the vertical mast
Diameter of the vertical mast

When mounting 2 WMT700 wind sensors at the same height, make sure that there is a minimum of 10 m of distance between the 2 sensors. If the difference in the height of the sensors is at least 0.5 m, it is enough to have a minimum distance of 2 m between the 2 sensors to avoid possible acoustical interference between them.

WARNING To protect personnel and the wind sensor, install an air terminal with the tip at least 1 m above WMT700. The rod must be properly grounded, compliant with all local applicable safety regulations. Do not install the wind sensor above the top of the air terminal.