SENSOR INSTALLATION GUIDE In order to achieve validate and reliable data from the sensors adequate place and installation is needed. To this purpose, Installation Guides were developed by the World Meteorological Organization and the U.S. National Weather Service. Following please find some recommendations:

Speed and wind direction:

· The standard height for wind measurement is 10 meters over ground level. In some particular applications (as in forestall fires), it is 6 meters.

· The distance between the sensor and any obstruction (natural or artificial), should be at least 10 times the height of obstruction.

· If the sensor is mounted on top of a building, it should be installed 1.5 times the height of the building to avoid the distorted air flow.

· In tall buildings, this is not always possible to accomplish, so it is recommended to attach it to a pole 3.5 to 5 meters high and on the side from where the strongest wind flow comes.

· If the sensors are mounted on a tower, over a stand, the stand should be 2 times the diameter or diagonal of the tower in length. It is also recommended to install it on the side from where the strongest wind flow comes.

Temperature and humidity:

· The standard height for installing these sensors is of 1, 25 to 2 meters, over the ground level, however because of special requirements other heights can also be used.

· The floor bellow the sensors should be natural soil or grass, but never concrete or asphalt.

· The area bellow the sensor should be open at least 9 meters in diameter, and hills, slopes and holes should be avoided.

· The distance between the sensors and any obstruction (natural or artificial), should be at least 4 times the height of the obstruction.

· If it is mounted on a tower, the stand should be at one time the diameter or diagonal of the tower.

· Temperature sensors should have the aspiration entrance looking downwards.

Solar Radiation:

· It is convenient to locate the sensor over a high platform or on top of a building.

· The place should be free of any obstruction that may cause shadows over the sensor.

· Colored walls should be avoided, as well as artificial radiation sources.

Precipitation:

· Precipitation sensors should be mounted in a way that the base remains horizontal. It is normally installed with the mouth 1.5 meters from the ground.

· The area around the sensor should be natural vegetation or crushed stone. Pavement should be avoided because it can cause splashing.

· The distance between the sensor and any obstruction to the wind should be at least two times the height of the obstruction.

· In open areas, the use of wind stoppers is highly recommended.