RBRconcerto³ CTD Conductivity temperature depth sensor
RBRconcerto³ C.T.D

RBRduo³ and RBRconcerto³: C.T, C.T.D, C.T.D++

Our flexible, option-packed loggers dedicated to salinity and more.

C.T conductivity, temperature sensors
C.T.D conductivity, temperature, pressure (depth) sensors
C.T.D + C.T.D plus one additional sensor
C.T.D ++ C.T.D plus two additional sensors

Available sensors:

Conductivity (C), Temperature (T), Pressure (D), Dissolved Oxygen (DO), Optical Dissolved Oxygen (ODO), Photosynthetically Active Radiation (PAR), Radiometer (rad), Turbidity (Tu), Thermistor string (Tx), Fluorescence (Fl), pH, Oxidation-Reduction Potential (ORP), Methane, Carbon Dioxide, Transmittance, Voltage

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RBRduo³ C.T and RBRconcerto³ C.T.D

The RBRduo³ C.T and RBRconcerto³ C.T.D are built on the years of experience RBR has creating reliable and easy-to-use instruments. They are uniquely designed to determine salinity by measuring the conductivity and temperature of water. Equipped with a pressure channel, the RBRconcerto³ C.T.D can also derive depth, density anomaly, and speed of sound. These self-contained, accurate, and autonomous submersible instruments can be deployed for a period of up to five years at 1min sampling intervals, and the data is retained in memory even after the batteries are removed.


Conductivity measurements are performed using a rugged inductive cell suitable for deployment in marine, estuarine, or fresh water. There are no exposed contacts, which avoids susceptibility to corrosion, and the housing may be frozen into ice without damage. It is characterized for the mechanical effects of both temperature and pressure to allow for accurate correction in salinity derivation. These coefficients are provided for customers who prefer to calculate their own corrections. In addition, it is suitable for use outside the usual realms of PSS-78 practical salinity scale, in applications such as desalination brine monitoring. The conductivity readings are temperature-corrected.

For profiling applications, the co-located thermistor reduces salinity spiking, thus increasing data accuracy. 

Equipped with a piezoresistive pressure channel, the CTD instruments provide more accurate salinity data when the instrument is sampling at varying depths.  

Additional sensors

A diversity of sensor configurations allows the instrument to be fine-tuned for a wide variety of applications. Variants with pressure, temperature, conductivity, radiometer, PAR, and turbidity sensors are also available in titanium housing, designed to endure harsh conditions.

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