OTT HydroMet KIPP & ZONEN SMP12, Руководство по эксплуатации

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Assembly | 5
SMP12 Smart Pyranometer | EN 27
5 Assembly
5.1 Installation for measuring global radiation
5.1.1 Choosing a site
There should be no obstructions to the field of vision above the pyranometer’s sensor element. If this is not
possible, the location of the pyranometer must be chosen to ensure that obstacles do not rise by more than
5 degrees above the azimuth range between sunrise after the shortest night and sunset on the longest day.
The 5 degrees correspond to a minimum distance from the pyranometer to the obstacle of 10 times the height
of the obstacle:
h
>10 x h
Fig. 2: Minimum distance from pyranometer to obstacle
The minimum distance is important for measuring the direct radiation. The diffuse solar radiation is not so
affected by obstacles near the horizon. An obstacle to the field of vision that rises 5 degrees over the entire
azimuth range of 360 degrees reduces the diffuse radiation directed downwards by only 0.8%.
4
Position the pyranometer in such a way that no shadows fall on it, for instance from masts.
4
Avoid hot exhaust gases with a temperature of over 100 °C in the proximity of the pyranometer. The
radiation can cause measurement deviations.
4
Do not position the pyranometer in front of light-colored walls or any other objects that reflect the
sunlight or emit short-wave radiation.