SP-722-SS Modbus Digital Output Thermopile Albedometer

Apogee's new Modbus albedometer is a cost-effective solution for horizontal and plane of array performance monitoring of bifacial solar panels. Consisting of an Apogee Instruments SP-510 and SP-61

  • Product Name:SP-722-SS Modbus Digital Output Thermopile Albedometer
  • Item No.:SP-722-SS
  • Manufacturers:Apogee
  • Country of Origin:USA

Apogee's new Modbus albedometer is a cost-effective solution for horizontal and plane of array performance monitoring of bifacial solar panels. Consisting of an Apogee Instruments SP-510 and SP-610 thermopile pyranometer, the SP-722-SS can be easily mounted to a mast or directly to a solar panel with one of the available mounting brackets.

The SP-722-SS is a thermopile albedometer with a digital signal using Modbus RTU protocol over RS-232 or RS-485. For mounting directly to a solar panel, we recommend using the AM-150 albedometer solar panel clamping bracket. To mount to a mast, use the AM-500 Net Radiometer mounting bracket or the AM-240 Rod based mounting fixture.

Albedo measurements indicate the broadband shortwave reflectivity of materials and are used to monitor bifacial solar panels, understand heat retention in urban and architectural settings, and study climate and weather. Typical applications for pyranometers include shortwave radiation measurement in agricultural, ecological, and hydrological weather networks.

The SP-722-SS includes an IP68 marine-grade stainless-steel cable connector to simplify sensor removal and replacement for maintenance and recalibration.


ISO 9060:2018Class C (upward-looking), N/A (downward-looking)Power Supply5.5 to 24 V DCCurrent DrawRS-232 quiescent 37 mA, active 37 mA; RS-485 quiescent 37 mA, active 42 mACalibration Uncertainty± 5 %Output RangeModbusMeasurement Range0 to 2000 W mˉ²Measurement RepeatabilityLess than 1 %Long-term DriftLess than 2 % per yearNon-linearityLess than 1 %Field of View180˚ (upward-looking), 150˚(downward-looking)Spectral Ranges385 nm to 2105 nm (upward-looking), 370 nm to 2240 nm (downward-looking)Directional (Cosine) ResponseLess than 30 W mˉ² at 80˚ solar zenith (upward-looking), Less than 20 W mˉ² for angles between 0 to 60˚ (downward-looking)Temperature ResponseLess than 5 % from -15 to 45 CZero Offset ALess than 2 W mˉ², Less than 10 W mˉ² (heated) (upward-looking); Less than 1 W mˉ², Less than 5 W mˉ² (heated) (downward-looking)Zero Offset BLess than 5 W mˉ²Uncertainty with Daily TotalLess than 5 %Operating Environment-50 to 80 C; 0 to 100 % relative humidityHeater390 Ω, 30.8 mA current draw and 370 mW power requirement at 12 V DCDimensions66.5 mm height, 74.4 mm length, 33 mm widthMass (with 5 m of cable)247 gCable5 m of four conductor, shielded, twisted-pair wire; additional cable available in multiples of 5 m; TPR jacket (high water resistance, high UV stability, flexibility in cold conditions); pigtail lead wiresWarranty4 years against defects in materials and workmanshipManufacturedMade in the USA