RBRcentauro³ C.T.D

The RBRcentauro³ is a small CTD instrument optimised for gliders and autonomous underwater vehicles. It incorporates conductivity, temperature, and pressure/depth sensors (CTD) and can derive salinity, density, and sound velocity. The instrument ensures totally silent operation for passive acoustic listening and turbulence measurements, and has an additional advantage of a transverse conductivity cell, optimised for natural hydrodynamic flow. The RBRcentauro³ C.T.D is unaffected by surface contaminants or freezing conditions, comes pre-calibrated to account for static conductive elements, and is rated to 2000m.

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Fig. 1.    RBRcentauro³ C.T.D, integrated

Key features of the RBRcentauro³ C.T.D are:

  • High accuracy

    • Unaffected by surface contaminants

    • Pre-calibrated to account for static elements1

    • Sampling rate up to 16Hz

  • Low power

    • 90% less power than pumped CTD

    • Longer mission and more samples

  • Silent operation

    • No pump or moving parts

    • Reduced noise for acoustic measurements

    • Reduced vibration for turbulence studies

1 Accuracy of conductivity measurements is affected by objects within 15cm of the sensor, especially if they are conductive. Metal deployment frames are a good example. This proximity effect decreases with distance. Calibration procedure uses the predetermined k-factor to take into account static elements, such as other sensors or glider body.

The RBR CTD instruments are uniquely designed to determine salinity by measuring the conductivity and temperature of the water. Their rugged inductive cell is not affected by surface contaminants or freezing conditions. The co-located thermistor improves data accuracy and reduces salinity spikes. Equipped with a piezoresistive pressure channel, the CTD instruments provide more accurate salinity data when the instrument is sampling at varying depths.

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Fig. 2.    RBRcentauro³ C.T.D. Left: temperature sensor, middle: conductivity sensor, right: pressure sensor

The RBRcentauro³ C.T.D facilitates optimal measurement schedules. Power consumption is 90% lower than that of traditional pumped CTD sensors and allows for substantially longer deployments. The calibration coefficients are stored on the instrument. With serial output, stream your data to your underwater vehicle or use Ruskin to download the RSK file. Datasets can be read directly in Matlab, or exported to Excel, OceanDataView®, or text files. See Ruskin User Guide: Standard Instruments³ and Logger³ Command Reference.

In addition to the RBRcentauro³, RBR offers other options for vehicle integration applications. Explore the capabilities of the RBRlegato³, an exceptionally small CTD instrument, whose unique shape is optimised for flow dynamics. Refer to the RBRlegato³ Instrument Guide.