SN-500-SS: Net Radiometer

Apogee Instruments' new four-component net radiometer provides individual measurement of net radiation components.

  • Product Name:Net Radiometer
  • Item No.:SN-500-SS
  • Manufacturers:Apogee
  • Country of Origin:USA

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.

net-radiometer-components.jpg

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 %