RBRduo & RBRconcerto | C.T, C.T.D, C.T.D++

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

  • Standard sampling up to 1Hz
  • ~30M readings standard; ~120M readings optional
  • External power option
  • USB 2.0 download
  • Optional Wi-Fi and twist activation
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

Additional Sensors:
Conductivity, Temperature, Pressure (Depth), Dissolved Oxygen, Fluorescence, Nitrate, ORP, PAR, pH, Transmissance, Turbidity, Voltage, Water Sampler

RBRduo C.T

The RBRduo C.T conductivity and temperature logger is our  CT logger built on the years of experience RBR has creating reliable and easy-to-use instruments. Salinity is derived through post-processing with the software supplied. A self-contained, accurate and autonomous submersible instrument, it can be deployed for a period of up to 5 years at 1 minute sampling intervals and data is retained in memory even without batteries.

RBRconcerto C.T.D

The RBRconcerto C.T.D conductivity, temperature and depth logger is our redesigned CTD logger built on the years of experience RBR has creating reliable and easy-to-use instruments. Salinity, depth, and speed of sound are derived through post-processing with the software supplied. The RBRconcerto C.T.D is a submersible instrument that is self-contained, accurate and autonomous; it can be deployed for a period of up to 5 years at 1 minute sampling intervals and data is retained in memory even after the batteries are removed.

About the sensors

Conductivity is measured with an inductive sensor, 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 icea 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.

The temperature sensor is built and calibrated in-house using an aged thermistor. The temperature channel is calibrated an accuracy of ± 0.002°C (ITS-90) over the range -5 to +35°C. Extended range calibrations are available.

Pressure is measured with a piezo-resistive transducer with nickel based super alloy diaphragm to avoid corrosion. Accuracy is 0.05% of the full scale rating and achievable resolution is 0.001%.

|fast6 1-6Hz continuous sampling
|fast12 1-6Hz, 12Hz continuous sampling
Extended memory options Up to 60M readings or ~120M readings (total)

 

Physical
Power 8 or 16 CR123A 3V cells
Communication USB 2.0 or RS-232/485
Storage ~30M readings standard; up to ~120M readings optional
Clock accuracy ±60 seconds/year
Depth rating Plastic: 740m
Ti: 10,000m (titanium)
Diameter Plastic: 63.25mm
Ti: 60.3mm
Length ~355mm or 490mm
Weight (air) ~1000g
Weight (water) ~490g
Sampling period 1s to 24h (moored)
|fast6 option 1-6Hz (profiling)
|fast12 1-6Hz, 12Hz (profiling)
Conductivity (up to 2,000m)
Range 0-85mS/cm
Initial accuracy ±0.003mS/cm
Typical stability 10μS/cm/year
Resolution ~1μS/cm
Temperature
Range -5°C to 35°C
Initial accuracy ±0.002°C
Resolution <0.00005°C
Time constant ~1s (standard) or ~0.1s (optional)
Typical stability 0.002°C/year
Pressure (Depth)
Range 20 / 50 / 100 / 200 / 500 / 740 / 1000 / 2000 (dbar)
Initial accuracy ±0.05% full scale
Resolution <0.001% full scale
Time constant <0.01s
Typical Stability ~0.1%/year

For specifications on additional sensors: RBRvirtuoso