Visibility Sensor

Wide range of sensors designed for monitoring on roads and in tunnels. Models with a wide measuring range are available to detect fog and haze; models with both digital and analog outputs, as well as relays for activating external equipment to be integrated into intelligent transport systems and used to automatically switch warning signals in changing visibility conditions.

All models are also “Present weather” sensors, that is, they can measure the intensity of precipitation by providing the analysis of water particles: fog, rain, snow or mixed form.


  • Visibility and Present weather sensors (DPA305/311.1);
  • Only visibility sensor (DPA320);
  • Lens self-cleaning system by compressed air (DPA311.1);
  • Integrated relay output to activate alarms (DPA305);
  • Analogue output 4-20 mA (DPA305).
Model DPA305 DPA311.1 DPA320
Type Visibility meter and Present weather Visibility meter and Present weather Visibility meter
Principle Forward-scattering 45° Back-scattering Forward-scattering 45°
Measure Visibility MOR (Meteorological Optical Range) Visibility Visibility MOR (Meteorological Optical Range)

Default: 10 m...2 Km Selectable:

  • 10 m...10 Km
  • 10 m...20 Km
  • 10 m...32 Km
  • 10 m...50 Km
  • 10 m...75 Km
Default: 10 m...2 Km Selectable: 10 m...4 Km 10 m...7.5 Km