Vaisala Visibility Sensors PWD10, PWD20 and PWD20W

​Flashing lights can be disturbing, so it is smart to dim them to the optimal level. With the help of the Vaisala Visibility Sensor PWD20W you can conform to local regulations and at create a comfortable living environment for the surrounding community. Installed on top of the nacelle, the PWD20W detects visibility for onshore and offshore applications. Operators use the visibility information to make decisions  about dimming the obstruction lights.



    • Accurate measurement of visibility
    • Robust and versatile
    • Easy to install

    Visibility Sensor PWD20W for Wind Turbines:
    Obstruction lights are used for marking the Wind Turbines for aviation safety. Some countries have established regulations for reducing the intensity of the obstruction lights basing on visibility. Wind Turbines can be equipped with Vaisala Visibility Sensor PWD20W, which is designed for this application. Several manufacturers have chosen Vaisala PWD20W due to its robustness and versatility.

    Technical Specifications

     Technical Specifications

    Visibility (MOR) measurement


         Measurement range

    10 ... 2000 m (32 ft ... 1.2 miles)


     PWD20 and PWD20W:
         Measurement range

    10 ... 20 000 m (32 ft ... 12 miles)

    Operating environment

    ​Temperature ​-40...+60 °C


    0...100 %RH

    Inputs and outputs

    ​Outputs ​RS232, RS485, analog current, relay control

    ​Operating voltage ​12 VDC ... 50 VDC (electronics)
    24 VAC or 24 VDC for heater option

    ​Power consumption

    ​     PWD10, PWD20
         and PWD20W
    ​3 W (electronics with dew heater @ 12VDC)




    40.4 (w) x 69.5 (l) x 19.9. (h) cm
    (15.91" (w) x 27.36" (l) x 7.83" (h))

    ​Weight ​3 kg (7 lb)

    For complete specifications, please see the brochure or user guide in "Documents".