Install the sensor on a mast or pole adjacent to the road. For the most reliable measurements:
- Avoid obstacles between the sensor optics and the road surface.
- Aim the receiver to the North in the Northern hemisphere and to the South in the Southern hemisphere.
- Do not aim the sensor against traffic flow.
- Use a steep installation angle for the sensor.
- Ensure that the rising or setting sun does not cause reflections from the road surface to the sensor optics.
- Park stationary maintenance vehicles with flashing lights outside the sensor's measurement area.
| Keep the area in front of the sensor free
of any objects. |
If you can choose between different installation angles (α) and measuring distances (c), choose a short measuring distance.
| Dimension | Range |
|---|---|
| Measuring distance when visibility measurement is disabled | 2–15 m (6 ft 8 in – 49 ft 3 in) |
| Measuring distance when visibility measurement is enabled | 8–15 m (26 ft 3 in – 49 ft 3 in) |
| Installation angle from the horizontal line | 30–80° (35–65° recommended) |
| When visibility measurement is enabled, the minimum measuring distance is 8 meters (26 ft 3 in). If the measuring distance is shorter than that, the road surface may affect the visibility reading. Usually, it is easy to increase the distance by turning the sensor horizontally. |
| Height a (m) | Length b (m) | Installation angle α (°) | Measuring distance c (m) |
|---|---|---|---|
| 3 | 3 | 45 | 4.2 |
| 3 | 4 | 37 | 5.0 |
| 4 | 3 | 53 | 5.0 |
| 4 | 4 | 45 | 5.7 |
| 4 | 5 | 39 | 6.4 |
| 5 | 5 | 45 | 7.1 |
| 5 | 7 | 36 | 8.6 |
| 6 | 6 | 45 | 8.5 |
| 6 | 8 | 37 | 10.0 |
| 7 | 7 | 45 | 9.9 |
| 7 | 9 | 38 | 11.4 |
| 8 | 8 | 45 | 11.3 |
The diameter of the measuring area is proportional to the measuring distance:
- At 10 meters (32 ft 10 in), the diameter is 20 cm (8 in).
- At 5 meters (16 ft 5 in), the diameter is 10 cm (4 in).
You can also calculate the installation angle and the measuring distance as follows: