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.
- 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.
| In the Northern Hemisphere, point the sensor to the North, or at an angle of incidence higher than the local maximum solar elevation. This protects the sensor from direct solar beam reflection from a wet surface that could result in an increase in the surface temperature reading. |
If you can choose between different installation angles (α) and measuring distances (c), choose a short measuring distance.
| Dimension | Range |
|---|---|
| Measuring distance | 2–15 m (6 ft 8 in – 49 ft 3 in) |
| Installation angle from the horizontal line | 30–85° (35–65° recommended) |
| 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 150 cm (59 in).
- At 5 meters (16 ft 5 in), the diameter is 75 cm (30 in).
This area covers approximately 50 % of the total measured signal.
You can also calculate the installation angle and the measuring distance as follows: