TriOS OPUS UV Spectral Sensor

OPUS is a full spectrum sensor that can deliver reliable readings for nitrate, nitrite, COD, BOD, DOC, TOC, and a number of other parameters.


  • Internal compensation for temperature, turbidity, and organic substances
  • RS-485 Modbus RTU output for integration with data collection platforms
  • Optional W55 wiper cleans optics & reduces maintenance intervals


OPUS is a spectral sensor for the online measurement of nitrogen and carbon compounds. By analyzing a full spectrum, OPUS is able to deliver reliable readings for N-NO3, N-NO2, organic ingredients (COD, BOD, DOC, TOC) and a number of other parameters.

Substances with a specific absorption spectrum, such as nitrate and nitrite, can be used directly as elements of the spectral analysis group. For sum parameters, such COD, BOD, TOC and DOC, theoretical absorption spectra that TriOS has been able to determine over the course of its many years of experience have been stored. Using these parameters, a spectral analysis based on UV absorption can use only the portion that absorbs UV light. Therefore, the OPUS uses only equivalents, and the parameters have the “eq” suffix appended to them, (i.e. CODeq, BODeq, TOCeq and DOCeq). The spectral analysis group also contains correction spectra that take into account, for example, the effects of turbidity. Because the entire absorption spectrum is detected, parameters such as SAC254 (spectral absorption coefficient at 254nm) can also be calculated.

The OPUS is compatible with the G2 interface box, allowing fast and easy configuration of the sensors using a web browser. The sensor can be easily integrated into existing process control systems and external data loggers using the native RS-485 Modbus RTU output, and the optional W55 wiper reduces maintenance intervals by cleaning the optics before each measurement.


ImagePart#Product DescriptionQuote
12S4010012S40100OPUS UV spectral sensor with 10mm path length & stainless steel housing, 10m cablequick_quote
12S3010012S30100OPUS UV spectral sensor with 5mm path length & stainless steel housing, 10m cablequick_quote