Sunshine Duration sensor

The TSD Sunshine Duration Sensor measures sunshine status and duration. The WMO (World Meteorological Organization) defines the sunshine duration as the time during which the direct solar radiation exceeds the level of 120 W/m2. The measuring principle is based on the use of 16 sensors arranged in such a way that, in the presence of sun, at least one of the photo-detectors is exposed to
sun light directly from the sun (besides the diffusion component).
Those sensors which are not directly illuminated by the sun are used for the measurement of the diffused light that is subtracted from the measurement of the sensor which sees the sun directly to get direct radiation.
The cylindrical glass protects the sensors and the internal circuits of the instrument from the weather and at the same time provides an excellent transparency to sunlight. This solution avoids the use of mechanical moving parts and ensures high reliability in the time.
The TSD is available with both RS485-Modbus and SDI-12 outputs, and is also equipped with a separately powered and galvanically isolated electrical resistance which prevents the formation of condensation on the sensitive elements.