6450 solar radiation sensor is for use with a Vantage Pro 2 standard station (it is already included with the 6162 Vantage Pro2 Plus). It includes a built-in level and 2' (0.6 m) cable.
The sensor measures solar radiation and solar energy - ie, the strength or power of sunshine. It is required (together with an anemometer and a temperature/humidity sensor) if you wish to monitor evapotranspiration.
Note that the solar sensor measures global solar irradiance levels. This is the sun's strength in units of watts/square metre and the best objective measure of the sunshine's power. The VP console has no direct ‘hours of sunshine’ readout, although this can be calculated, to a first approximation, by the Weatherlink software from logged solar radiation data.
All Vantage Pro 2 stations - cabled and wireless - will accept the sensor, which is mounted on a small shelf assembly that sits alongside the rain gauge and that needs to be bought as a separate accessory item (6673, Sensor Mounting Shelf) The 6450 solar radiation sensor, together with the mounting shelf, is included pre-assembled in the VP2 Plus models.
Further details about using additional sensors are provided on the 'VP Supplementary Sensors, Stations and Accessories' page at our Main Site.