Benefits and Features
Thermopile sensor eliminates spectral errors associated with silicon-cell pyranometers
Much lower price point than other thermopile sensors
On-board sensor automatically detects if the C5320 is level for installation, diagnostics, and remote troubleshooting
Designed for long-term stability and deployment
Dome-shape sensor head allows dew and rain runoff
Internal heaterto reduce errors from dew, frost, rain, and snow
SDI-12 digital output
Detachable waterproof connector from sensor head for fast, easy servicing
Calibration data stored on sensor

Technical Description
The C5320 combines a blackbody thermopile detector with an acrylic diffuser. This design is a significant improvement when compared with the spectral response of silicon photocell pyranometers, while offering a comparable price. Thermopile pyranometers use a series of thermoelectric junctions (multiple junctions of two dissimilar metals following the thermocouple principle) to provide a signal of several pV/W/m² proportional to the temperature difference between a black absorbing surface and a reference. The thermopile pyranometer's black surface uniformly absorbs solar radiation across the solar spectrum.
The 0.2 W heater keeps water (liquid and frozen) off the sensort o minimize errors caused by dew, frost, rain, and snow blocking the radiation path. Dew and rain runoff is
faciliated by the dome-shaped sensor head (diffuser and body). This keeps the sensor clean and minimizes errors caused by dust blocking the radiation path. The sensor is housed in a rugged anodize aluminum body, and the electronics are fully potted.
The CS320 pyranometer has sensor-specific calibration coefficients determined during the custom calibration process. Coefficients are programmed into the microcontrollers at the factory. The CS320 has an SDI-12 output (SDI-12 version 14), where short-wave radiation (W/m²) is returned in digital format. Measurement of the C5320 pyranometer requires a measurement device with SDI-12 functionality that includes the M or C command.