Apogee Instruments’ silicon-cell pyranometers feature a silicon-cell detector. The sensors are accurate, stable, durable, and cost-effective, the results of continual refinement of design.

Accurate Measurements – ISO 9060:2018 Class C

Calibration in controlled laboratory conditions is traceable to the World Radiometric Reference in Davos, Switzerland. The upward-looking model is cosine corrected, with directional errors less than 20 W m-2 at 80° solar zenith angle. Long-term non-stability determined from multiple replicate pyranometers in accelerated aging tests and field conditions is less than 2 % per year.

Rugged, Self-cleaning Housing

Patented domed shaped sensor head (diffuser and body) facilitate runoff of dew and rain to keep the diffuser clean and minimize errors caused by dust blocking the radiation path. Sensors are housed in a rugged anodize aluminum body and electronics are fully potted.

Heated Option

A heated pyranometer (SP-230 All-season) is available with a 0.2 W heater to keep water (liquid and frozen) off the sensor and minimize errors caused by dew, frost, rain, or snow blocking the optical path.

Typical Applications

Applications include shortwave radiation measurement in agricultural, ecological, and hydrological weather networks. Sensors are also used to optimize photovoltaic systems.

Mounting

The AL-120 Solar Mounting Bracket with Leveling Plate facilitates mounting the sensor to a mast or pipe. The AL-100 Solar Sensor Leveling Plate is designed to level the sensor while sitting on a flat surface or mounting to a surface.

Output Options

Multiple analog and digital output options are available including: 0 to 350 mV, 0 to 2.5 V, 0 to 5 V, and 4 to 20 mA ranges. Digital output options include a digital ‘smart’ sensor that uses USB communication and custom software to interface directly to a computer, SDI-12, and Modbus protocols. The silicon-cell pyranometer is also available attached to a hand-held meter with digital readout. The analog version of this sensor (SP-110) works with our µCache Bluetooth Micro Logger.

High Quality Cable

Pigtail-lead sensors feature an IP68, marine-grade stainless-steel cable connector approximately 30 cm from the head to simplify sensor removal for maintenance and recalibration. Cable is shielded-twisted pair wire with a TPR jacket for high water resistance, UV stability, and flexibility in cold conditions.

Technical Specifications

 SP-110-SSSP-212-SSSP-214-SSSP-215-SSSP-230-SSSP-420SP-421-SSSP-422-SS
ISO 9060:2018Class C (previously known as second class)Class C (previously known as second class)Class C (previously known as second class)Class C (previously known as second class)Class C (previously known as second class)Class C (previously known as second class)Class C (previously known as second class)Class C (previously known as second class)
Power SupplySelf-powered5 to 24 V DC7 to 24 V DC5.5 to 24 V DC12 V DC for heater5 V5.5 to 24 V DC5.5 to 24 V DC
Current Draw-300 µA22 mA maximum; 2 mA quiescent300 µA15.4 mA61 mA when logging1.5 mA (quiescent); 1.9 mA (active)RS-232 37 mA;
RS-485 quiescent 37 mA, active 42 mA
Output (Sensitivity)0.2 mV per W m-21.25 mV per W m-20.008 mA per W m-22.5 mV per W m-20.2 mV per W m-2---
Output Type0 to 400 mV0 to 2.5 V4 to 20 mA0 to 5 V0 to 400 mVUSBSDI-12Modbus
Resolution-----0.1 W m-2--
Calibration Factor (Reciprocal of Output)5 W m-2 per mV0.8 W m-2 per mV125 W m-2 per mA, 4 mA offset0.4 W m-2 per mV5 W m-2 per mVCustom for each sensor and stored in the firmwareCustom for each sensor and stored in the firmwareCustom for each sensor and stored in the firmware
Calibration Uncertainty at 1000 W m-2Less than 3 %Less than 3 %Less than 3 %Less than 3 %Less than 3 %Less than 3 %Less than 3 %Less than 3 %
Measurement RepeatabilityLess than 1%Less than 1%Less than 1%Less than 1%Less than 1%Less than 1%Less than 1%Less than 1%
Long-term DriftLess than 2 % per yearLess than 2 % per yearLess than 2 % per yearLess than 2 % per yearLess than 2 % per yearLess than 2 % per yearLess than 2 % per yearLess than 2 % per year
Non-linearityLess than 1 % up to 2000 W m-2Less than 1 % up to 2000 W m-2Less than 1 % up to 2000 W m-2Less than 1 % up to 2000 W m-2Less than 1 % up to 2000 W m-2Less than 1 % up to 2000 W m-2Less than 1 % up to 2000 W m-2Less than 1 % up to 2000 W m-2
Response TimeLess than 1 msLess than 1 msLess than 1 msLess than 1 msLess than 1 msSoftware updates every secondLess than 0.6 s-
Field of View180°180°180°180°180°180°180°180°
Spectral Range360 to 1120 nm360 to 1120 nm360 to 1120 nm360 to 1120 nm360 to 1120 nm360 to 1120 nm360 to 1120 nm360 to 1120 nm
Directional (Cosine) Response± 5 % at 75° zenith angle± 5 % at 75° zenith angle± 5 % at 75° zenith angle± 5 % at 75° zenith angle± 5 % at 75° zenith angle± 5 % at 75° zenith angle± 5 % at 75° zenith angle± 5 % at 75° zenith angle
Temperature Response0.04 ± 0.04 % per C0.04 ± 0.04 % per C0.04 ± 0.04 % per C0.04 ± 0.04 % per C0.04 ± 0.04 % per C0.04 ± 0.04 % per C0.04 ± 0.04 % per C0.04 ± 0.04 % per C
Operating Environment-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m
Dimensions24 mm diameter, 33 mm height30.5 mm diameter, 37 mm height30.5 mm diameter, 37 mm height30.5 mm diameter, 37 mm height24 mm diameter, 33 mm height24 mm diameter, 33 mm height30.5 mm diameter, 37 mm height30.5 mm diameter, 37 mm height
Mass (with 5 m of cable)90 g140 g140 g140 g90 g90 g140 g140 g

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