Sunshine Duration Sensors
Sunshine Duration Sensors PCTEL001 are widely used in weather network. Sunshine duration is defined by World Meteorological Organisation (WMO) as the time during which the direct solar radiation exceeds the level of 120W/m² and is normally measured in hours. In agronomy the amount of sunshine received by crops can be used to help forecast yields. In bulding automation the sensors can be used as an input to the systems for the control of the internal environment, such as the deployment of sun blinds.
The PCTEL001 measures solar radiation through a high quality glass tube. It has no moving parts and uses 3 photo-diodes with specially designed diffusers to make an analogue calculation of when it is sunny. The output is switched high or low to indicate sunny or not sunny conditions. The calculated direct irradiance is also available.
It is engineered for continuos outdoor use and is easy to install and service. The standard cable is 15m., 25m. is an option. The large drying cartridge with screw-on cap gives extended change intervals and a humidity indicator shows clearly when this is necessary.
The sensors operates from 12VDC power and has two levels of built-in heating to dissipate rain, snow and frost. These are normally switched externally, but an optional internal thermostat is available. A robust mounting arm is fitted to the base of the instrument.