• Minimum clearance of 100 m (328 ft) from all large buildings and other structures that
generate heat and obstruct precipitation droplets.
• Avoid the shade of trees because the trees may cause changes in the microclimate.
Reflective Surfaces
Make sure that the site is free of reflective surfaces disturbing the optical measurement.
• If obstacles reflect the transmitter beam back to the receiver unit, the sensor indicates
too low MOR values because the
reflected signal cannot be distinguished from the
scatter signal.
• Rotate the sensor cross arm and check the visibility readings.
If there are
reflections, the corresponding visibility reading changes depending on the
cross arm orientation.
• On the roadside:
• Do not aim the receiver against the
trac flow. Possible reflections from the passing
cars can generate false snow detections in the winter.
• Ensure that the rising or setting sun does not cause
reflections from the road surface
to the receiver.
Contamination
Make sure that the site is free of obvious sources of contamination, especially when placing
the sensor next to a road.
• Face the transmitter and receiver away from contamination sources, such as spray from
passing vehicles.
• Dirty lenses cause the sensor to report too high visibility values.
• The sensor automatically detects excessive contamination.
Bright Lights
Do not point the receiver or transmitter toward powerful light sources. The receiver circuit
may become saturated in bright light, in which case the built-in diagnostics indicate a
warning.
• Bright daylight increases the noise level in the receiver. Vaisala recommends pointing
the receiver North in the Northern Hemisphere, and South in the Southern Hemisphere.
• Park stationary maintenance vehicles with
flashing lights outside the sensor's
measurement area.
Powering and Heating
Make sure power supply and communication lines are available, as this influences the
amount of work and accessories needed, and installation cost.
For very harsh winter conditions, use the optional hood heaters to prevent ice and snow
accumulation.
More Information
‣
Placing Meteorological Sensors (page 23)
AWS310/AWS310-SITE Installation Manual M211584EN-F
132
To Next Page
Loading...
Need help?
General
