This SUNA V2 was deployed in a fixed position near the surface of the river. Although all seemed well at the deployment site—the optical path was completely submerged, and previous deployments at this depth were successful—small changes in water level were enough the periodically expose the sensor’s optical path to open air, eliciting the zero-nitrate response. Lowering the SUNA V2 deeper into the pipe eliminated the downward data spikes. After all, the SUNA V2 measures dissolved nitrate, not nitrogen gas. The figure above shows the same dataset with downward spikes filtered out.
The SUNA V2 has flexible deployment options, ranging from moored freshwater deployments to blue-ocean profiling applications. With telemetry options including RS-232, USB, SDI-12, and analog output; the SUNA V2 can be installed on a variety of platforms.
Download our Technical Note to learn how to conduct real-time profiles by calibrating the SUNA V2’s analog output for use with a Sea-Bird Scientific profiling CTD.