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SENSOR INSTALLATION
Please consider the following factors when choosing a location for the sensor.
Direct and Reflected Light
–
Care should be taken to ensure that the sensor is situated
with the receiver facing away from any direct sunlight (rising and setting sun) and any
surfaces which could cause reflections of the IR (Infrared) illumination from the transmitter
(for example walls, bridges, trees and people, etc.). Reflected IR illumination entering the
sensor’s optics can cause errors in the reported visibility meas
urements.
Air-flow
–
Care should be taken to ensure that the sensor is situated away from objects
that disrupt the 'normal' flow of air to and through the sensor sampling volume (for example
walls, trees and other equipment, etc.).
It is recommended for the RWS sensor:
•
To be mounted with the sensor facing away from the traffic, not less than 3 metres
away from a road, to avoid spray contaminating the lenses.
•
No vegetation (trees, large bushes) within 3 metres in front of the sensor, this is to
avoid IR reflections, and no vegetation 1 metre below the sensor.
•
The sensor is located at a site where it is safe to install and maintain.
Suggested siting
If the above siting is not possible, ensure the Sensor is facing the same direction as the
closest traffic.
