Vaisala Present Weather Detectors PWD12 and PWD22
Vaisala Visibility Sensors PWD10 and PWD20   

The Vaisala PWD-series of Present Weather and Visibility Sensors give road and aviation authorities and meteorological organizations the mix they require of visibility measurement range (MOR), characterization of reduced visibility, precipitation type identification, precipitation accumulation/intensity measurement, and report formats (WMO, NWS code tables). The measurement capabilities of the Vaisala PWD-series sensors can be extended when measurement needs grow. All sensors can be economically upgraded to ensure that the sensor gives full value for many years to come.

The measurement range of the Vaisala Visibility Sensors PWD10 and PWD20 varies from 10 - 2,000 meters to 10 - 20,000 meters depending on the model. The PWD10 is an ideal choice for road weather applications whereas PWD20 can be used for diverse applications covering harbors, coastal areas, heliports and windmill parks.

Vaisala Present Weather Detectors PWD12 and PWD22 are two-in-one forward scatter visibility and present weather sensors. The visibility measurement range of the sensors varies from 10 - 2,000 meters to 10 - 20,000 meters depending on the model. The PWD12 is an ideal choice for road weather applications. The PWD22 is recommeded for automatic weather stations that are used for general meteorological applications and aviation applications. The PWD22's ability to detect freezing precipitation and to report present weather in WMO METAR code format makes its as an valuable addition to AWOS systems.

Technical specifications

Present weather
PWD12	Identifies 4 different types of precipitation (rain, drizzle, mixed rain/snow, snow
	Fog, mist, haze (smoke, sand) or clear
	Reports WMO 4680 (SYNOP) and NWS code tables 39 different codes supported from WMO 4680 code table
PWD22	Identifies 7 different types of precipitation (rain, freezing rain, drizzle, freezing drizzle, mixed rain/snow, snow, ice pellets)
	Fog, mist, haze (smoke, sand) or clear
	Reports WMO 4680 (SYNOP), 4678 (METAR) and NWS code tables 49 different codes supported from WMO 4680 code table
Visibility
PWD10 and PWD12	Measurement range (MOR) 32... 6 500 ft (10...2 000 m)
PWD20 and PWD22	Measurement range (MOR) 32...65 000 ft (10...20 000 m)