Sea-Bird Scientific SUNA Optical Nitrate Sensor

High accuracy in-situ nitrate measurement

Description

With improved optics and built-in adaptive sampling intelligence, the SUNA V2 measures nitrate with industry-leading accuracy and stability over a wide range of environmental conditions. The wide range of optional features offered for the SUNA V2 make the sensor a cost-effective choice for routine nitrate measurements.

  • Attended, Unattended
  • Nitrate
  • High-accuracy, chemical-free, in-situ nitrate measurement
  • SDI-12, RS-232

Advantages

Optional: reduced 5mm pathlength for improved performance during high flow/high turbidity storm events

  • Adaptive sampling logic automatically tunes the optical operations to real-time environmental conditions for high CDOM applications
  • Active fouling control with fully integrated biowiper, ensuring accurate and stable long-term data sets, reducing the need for site visits
  • Advanced processing algorithms, using the full UV spectrum for maximum accuracy across the entire sensing range

Resources

Sea-Bird Scientific SUNA Brochure
Sea-Bird Scientific SUNA Manual
Nutrient Monitoring Infographic
Chester River Nutrient Monitoring Article
In-Situ Nutrient Monitoring Article
Sea-Bird Scientific SUNACOM Software Manual
Nutrient Monitoring App Note

Technical Data

Mechanical SUNA with Wiper
Material Titanium
Rated Depth 100 m
Weight (in air) 4.8 kg
Pathlength 10 mm or 5 mm
Length 588 mm/ 583 mm
Diameter 63 mm
Temp Range, Operation -2 – 35 °C
Temp Range, Storage -20 – 50 °C
Electrical
Input 8 – 18 VDC
Input, Sensor with Wiper 8 – 15 VDC
Current Draw, Operation ~ 625 mA at 12V
Current Draw, Standby ~ 20 mA at 12V
Light Source UV Deuterium Lamp (900 hr lifetime)
Communication Interface RS232; Analog 4 – 20 mA; (USB, SDI-12 optional)
Data Storage 2GB (optional)
Optical
Spectral Range 190-370 nm
Pathlength 10 mm (5 mm optional)
Nitrate Measurement Accuracy
Concentration Range 10 mm pathlength
Calibration Sensor Specific*
up to 14 mg N/L 0.028 mg N/L or 10%
up to 28 mg N/L 0.028 mg N/L or 15%
up to 42 mg N/L 0.028 mg N/L or 20%
up to 56 mg N/L out of range
Calibration Class Based**
up to 14 mg N/L 0.035 mg N/L or 20%
up to 28 mg N/L 0.035 mg N/L or 25%
up to 42 mg N/L 0.035 mg N/L or 30%
up to 56 mg N/L out of range
Concentration Range 5 mm pathlenght
Calibration Sensor Specific*
up to 14 mg N/L 0.056 mg N/L or 10%
up to 28 mg N/L 0.056 mg N/L or 15%
up to 42 mg N/L 0.056 mg N/L or 15%
up to 56 mg N/L 0.056 mg N/L or 15%
Calibration Class Based**
up to 14 mg N/L 0.063 mg N/L or 20%
up to 28 mg N/L 0.063 mg N/L or 25%
up to 42 mg N/L 0.063 mg N/L or 25%
up to 56 mg N/L 0.063 mg N/L or 25%
* A sensor specific calibration uses extinction coefficients from the sensor itself
** A class based calibration uses extinction coefficients that are the averager of many sensors
Nitrate Measurement Precision
Processing Configuration Seawater or Freshwater with T-S Correction
Short-term precision (3 sigma) 0.004 mg N/L
Change (“drift”) per hr of lamp time <0.004 mg N/L
Processing Configuration Seawater (0-40PSU)
Short-term precision (3 sigma) 0.034 mg N/L
Change (“drift”) per hr of lamp time <0.014 mg N/L
Limit of Detection and Limit of Quantification
Processing Configuration Seawater or Freshwater with T-S Correction
Limit of Detection 0.004 mg N/L
Limit of Quantification 0.014 mg N/L
Processing Configuration Seawater (0-40 PSU)
Limit of Detection 0.034 mg N/L
Limit of Quantification 0.112 mg N/L

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