View All Sea Bird View All Hydrolab Products View All OTT Products View All ADCON Products View All Van Essen Products View All Eijkelkamp Products View All Turner Products View All Turner Products

The Sea-Bird Coastal SUNA V2 is based on the ISUS (In-Situ Ultraviolet Spectroscopy) UV nitrate meter developed at MBARI. Satlantic adapted the design to develop the SUNA V2 to measure nitrate in increasingly challenging waters, including extremely turbid and high CDOM waters.

With improved optics and built-in adaptive sampling intelligence, the SUNA V2 nitrate meter measures nitrate in the water with industry-leading accuracy and stability over a wide range of environmental conditions, from blue-ocean nitraclines to storm runoff in rivers and streams.

The SUNA V2 nitrate meter is the ultimate solution for real-time reagent free nutrient testing. The wide range of optional features and factory calibration offered for the SUNA V2 make the nitrate meter a cost-effective choice for routine water quality tests.

See more information on the use of optical sensors to measure nitrate, including an example from the Mississippi, from the USGS here- Continuous Nitrate Monitoring in Rivers.

You can also watch a presentation from a recent water quality monitoring conference on the use of UV nitrate sensors for continuos monitoring here- In Situ Monitoring of Nitrate from Agricultural Fields to Estuaries

  • 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




Limit of Detection

0.5 µM (FW or SW with T/S correction) 
2.0 µM (SW 0-40 psu)

Detection Range

3000 µM (10 mm path length)
4000 µM (5 mm path length)


± 2 µM (± 0.028 mg/I-N) or ± 10% of reading

Short-term precision

0.3 µM (FW or SW with T/S correction)
2.4 µM (SW 0-40 psu)

Drift (per hour lamp time)

0.3 µM (FW or SW with T/S correction)
1.0 µM (SW 0-40 psu)

Turbidity range

625 NTU* (10 mm path length; absent other absorbing species)
1250 NTU (5 mm path length; absent other absorbing species)



Path Length

10 mm & 5 mm (high turbidity option)

Wavelength Range

190 ... 370 nm

Lamp Type

Continuous Wave, Deuterium Lamp

Lamp Lifetime

900 h



Input Voltage

8 ... 18 VDC & 8 ... 15 VDC with Hydro-Wiper

Power Consumption

7.5 W (0.625 A at 12 V) nominal




Class-based Freshwater


Real-Time temperature-salinity correction available* (0 ...35°C, 0 ... 40 PSU)

* Requires external T/S data.

Related Categories
Water Quality Multiprobes
Aqualab Systems