Nitrate Sensor
TriOS NICO®
Most affordable nitrate monitoring unit. Low-cost UV photometer for online NO₃ measurement in lakes, rivers, drinking water, and wastewater. Xenon flash lamp source.
Full specifications →Nitrate Probes
UV photometric nitrate sensors for lakes, rivers, drinking water, and wastewater
Not sure which probe is right for you?
Use our interactive Nitrate Probe Configurator — select your water type, parameters, path length, housing, and accessories to get a complete part number list you can print or submit directly to us.
Need to validate your NICO or OPUS probe?
Use our NPC Service Calculator to validate reference voltages and absorbance values.
Spectral Sensor
TriOS OPUS®
Full UV spectrum sensor (0.8 nm/pixel). Measures NO₃-N, NO₂-N, COD, BOD, DOC, TOC, and more. G2 interface with web browser configuration. WiFi & Ethernet connectivity.
Full specifications →
Accessories
NICO/OPUS Accessories
G2 interface, G2plus, G2 air interface, SDI-12 converter, Wiper W55, wiper blades, bulkhead, custom Trios cables, FlowCell, ValTub, TriBox 3, TriBox Mini.
Selection Guide
NICO vs. OPUS — Which is right for you?
| Feature | NICO® | OPUS® |
|---|---|---|
| Technology | UV photometer (4 photodiodes) | Full UV spectrum (0.8 nm/pixel) |
| Parameters | NO3-N, NO3, NOx-N, NOx | NO3, NO2, COD, BOD, DOC, TOC, TSS, and more |
| Light Source | Xenon flash lamp | Deuterium lamp |
| Connectivity | Ethernet, RS-485 Modbus RTU | Ethernet, RS-485, WiFi (optional) |
| Best For | Cost-effective single-parameter nitrate | Multi-parameter N & C monitoring |