Apogee Instruments' new four-component net radiometer provides individual measurement of net radiation components. The sensor features an SDI-12 output, eliminating the need for multiple analog channels to measure the individual components of net radiation. The net radiometer comes as a complete package that includes net radiometer, mounting rod, pigtail lead cable for datalogger interface, and carrying case.
Onboard A/D Conversion and SDI-12 Output
Apogee net radiometers feature onboard A/D conversion and SDI-12 output to eliminate the requirement of multiple analog datalogger channels.
Four-component Net Radiometer
An upward-looking and downward-looking pyranometer, and an upward-looking and downward-looking pyrgeometer provide separate measurements of the four components of net radiation.
Individually Heated Radiometers
Each radiometer includes an individual heater to increase accuracy by minimizing the influence of dew/frost on the filter.
Compact and Light Weight
Designed to be light weight and small in size to facilitate easy mounting.
SN-500 Specifications
Input Voltage Range 5.5 to 16 V DC (heaters are optimized to run at 12 V DC)
Current Draw (12 V DC Supply Voltage) Heaters on, communication enabled: 63 mA; Heaters off, communication enabled: 1.5 mA; Heaters off, communication disabled: 0.6 mA
Response Time (using SDI-12 Protocol) 1 s (SDI-12 data transfer rate; detector response times are 0.5 s)
Heaters (sensors individually heated) 62 mA current drain and 740 mW power requirement at 12 V DC
Operating Environment -50 to 80 C; 0 to 100 % relative humidity
Dimensions 116 mm length, 45 mm width, 66 mm height
Mass 320 g (with mounting rod and 5 m of lead wire)
Cable M8 connector (IP68 rating) to interface to sensor housing, 5 m of four conductor shielded, twisted-pair wire in a santoprene rubber jacket with pigtail lead wires
Pyrgeometer Specifications
Sensitivity 0.12 mV per W mˉ² (variable from sensor to sensor, typical value listed)
Calibration Factor (Reciprocal of Sensitivity) 8.5 W mˉ² (variable from sensor to sensor, typical value listed)
Calibration Uncertainty ± 5 %
Output Ranges -24 to 24 mV
Measurement Range -200 to 200 W mˉ² (net longwave irradiance)
Measurement Repeatability Less than 1 %
Long-term Drif t Less than 2 % change in sensitivity per year
Non-linearity Less than 1 %
Detector Response Time Less than 0.5 s
Field of View 150 ˚
Spectral Range 5 to 30 µm
Temperature Response Less than 5 % from -15 to 45 C
Window Heating Offset Less than 10 W mˉ²
Zero Offset B Less than 5 W mˉ²
Tilt Error Less than 0.5 %
Uncertainty in Daily Total ± 5 %
Temperature Sensor 3 0 kΩ thermistor, ± 1 C tolerance at 25 C
Output from Thermistor 0 to 2500 mV (typical, other voltages can be used)
Input Voltage Requirement for Thermistor 2500 mV excitation (typical, other voltages can be used)
Pyranometer Specifications
Sensitivity 0.057 mV per W mˉ² (upward-looking); 0.15 mV per W mˉ² (downward-looking), (variable from sensor to sensor, typical values listed)
Calibration Factor (Reciprocal of Sensitivity) 17.5 W mˉ² per mV (upward-looking); 6.7 W mˉ² per mV (downward-looking)
Calibration Uncertainty ± 5 %
Output Range 0 to 114 mV (upward-looking); 0 to 300 mV (downward-looking)
Measurement Range 0 to 2000 W mˉ² (net shortwave irradiance)
Measurement Repeatability Less than 1 %
Long-term Drift Less than 2 % per year
Non-linearity Less than 1 %
Detector Response Time 0.5 s
Field of View 180 ˚ (upward-looking); 150 ˚ (downward-looking)
Spectral Range 385 nm to 2105 nm (upward-looking); 295 nm to 2685 nm (downward-looking)
Directional (Cosine) Response Less than 30 W mˉ² at 80 ˚ solar zenith (upward-looking); Less than 20 % for angles between 0 and 60 ˚ (downward-looking)
Temperature Response Less than 5 % from -15 to 45 C
Zero Offset A Less than 5 W mˉ²; Less than 10 W mˉ² (heated)
Zero Offset B Less than 5 W mˉ²
Uncertainty in Daily Total Less than 5 %
