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Enabling better global research outcomes in soil, plant & environmental monitoring.

SNiP-NRA

The SNiP-NRA is a 'Sensor Node Integrated Package' for LoRaWAN communication of real-time measurements of net radiation, for continuous environmental monitoring (including plant light relations).

The SNiP-NRA

The base SNiP-NRA intergrates 1x S-NODE and 1x SN-500 Net Radiometer Sensor to a site’s unique network, communication and power requirements.

The SN-500 Net Radiometer is a self-powered lux sensor that measures net radiation in the range 0 to 2000 W m-2 (Net shortwave) and -200 to 200 W m-2 (Net longwave). Net radiation is a key variable in the surface energy balance and influences turbulent fluxes, including evapotranspiration. Applications include measurements on flux towers and weather stations.

 

See Further Specifications on the S-NODE
See Further Specifications on the SN-500 Net Radiometer Sensor

Further parameters can be added to the SNiP without requiring loggers to match each distinct sensor, substantially reducing the cost of getting a fuller picture on the application. The S-NODE can support an additional 3x sensors.

 

 

Typical Applications

Net radiation is a key variable in the surface energy balance and influences turbulent fluxes, including evapotranspiration. Applications include measurements on flux towers and weather stations.

Net radiation is the sum of the four components shown below (incoming shortwave, outgoing shortwave, incoming longwave, outgoing longwave). Incoming shortwave incident on the surface is either reflected or absorbed by the surface material, and longwave radiation is emitted from the surface and emitted from the molecules of air in the atmosphere. Typical clear sky summer fluxes over grass and clear sky winter fluxes over snow are shown. A typical summer flux at solar noon would be +650 W/m2; in winter it would be 0 W/m2.

Net Radiation

S-NODE

The S-NODE (for Environmental Monitoring) has been designed to support the broad suite of SDI-12 based environmental sensors. The S-NODE can support sensors with higher power requirements; a solar panel can charge either the internal lithium-ion battery or both the node and sensor can be powered by an external 12V system (e.g. battery or mains source).

A decoder suitable for TTN will be provided based upon sensor configuration.

  • LoRaWAN™ low-power long-range connectivity
  • Supports the full range of SDI-12 commands, and sensors requiring constant excitation.
  • Optional CAT-M1
  • Solar rechargeable Lithium-ion or external 12V power options
  • Optional Multi-constellation GNSS
  • AS923, AU915 and US915 available, with other region plans available upon request.
  • Standard IP65 enclosure, optional IP67

SN-500 Net Radiometer

  • 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.
  • 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 analogue datalogger channels.
  • Individually Heated Radiometers
    Each radiometer includes an individual heater to increase accuracy by minimising the influence of dew, frost and snow on the filter.
  • Compact and Light Weight
    Designed to be light weight and small in size to facilitate easy mounting.
  • Cost-effective
    Apogee’s net radiometer is low cost compared to other four-component net radiometers on the market.
Input Voltage Range: 5 to 16 V DC (heaters are optimised 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 time 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 (IP67 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 m-2 (variable from sensor to sensor, typical value listed)
Calibration Factor (Reciprocal of Sensitivity): 8.t W m-2 per mV
Calibration Uncertainty: ± 5%
Output Range: -24 to 24 mV
Measurement Repeatability: Less than 1%
Long-term Drift: Less than 2% change in sensitivity per year
Non-linearity: Less than 1%
Detector Response Time: 0.5 s
Field of View: 150°
Spectral Range: 5 to 30 µm (50% points)
Temperature Response: Less than 0.1 C-1
Window Heating Offset: Less than 10 W m-2
Zero Offset B: Less than 5 W m-2
Tilt Error: Less than 0.5%
Uncertainty in Daily Total: ± 5%
Temperature Sensor: 30 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 m-2 (upward-looking); 0.15 mV per W m-2 (downward-looking); (variable from sensor to sensor, typical values listed)
Calibration Factor (Reciprocal of Sensitivity): 17.5 W m-2 per mV (upward-looking); 6.7 W m-2 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 m-2 (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); (50% points)
Directional (Cosine) Response: Less than 20 W m-2 at 80° solar zenith
Temperature Response: Less than 0.1% C-1
Zero Offset A: Less than 5 W m-2; less than 10 W m-2 (heated)
Zero Offset B: Less than 5 W m-2
Uncertainty in Daily Total: Less than 5%

SN-500 Dimensions