Online Conductivity (Salinity) and Temperature Sensor

Mini CT salinity sensor for connection to embedded systems. Wide salinity range.

Conductivity (CT) sensor connection port for subsea device integration. For both short or long-term oceanographic surveys.

Key features

  • Smallest online conductivity sensor on the market
  • Real time data streaming or data retrieval after surveying
  • Fully submersible rugged design
  • Wide salinity range, low to high conductivity
  • Holds pressure from shallow to deep ocean
  • Description

    Smallest CT on the market

    The small and handy CT online is a modified version of the popular DST CT standalone data logger. The sensor probe is only 22.4 mm in diameter and 92 mm in length and a subsea cable connects to the connector end. The small measuring device is also available as a CTD online if depth measurements are required.


    The online CT sensor is used for hydrographic and oceaonographic studies:

    • Survey missions where it is a part of autonomous underwater vehicles (AUV), either streaming data in real-time or for later data retrieval when AUV is surfaced.
    • Long term stationary monitoring underwater where it is connected to a data logging system.
    • For using the CT without wired connection, as a self-contained logger, click here.
    • A CTD online version is also available.

    Fully submersible rugged design

    The housing is ruggedly designed for durability, strong breakage resistance and high pressure survival. The CT online has a robust plastic molding around the ceramic sensor housing and the housing has a threaded steel connector on the end. The subsea cable comes with a matching subsea connector for a quick and easy connection to the CT.

    Wide salinity range, low to high conductivity

    The DST CT online can capture conductivity from 3 to 68 mS/cm. Low conductivity range, 0.1-6 mS/cm, is also available, ideal for measuring in brackish water.

    Holds pressure from shallow to deep ocean

    The CT online logger can hold up to 2500 m depth. Otherwise if depth measurements are needed, customers choose between depth calibration ranges up to 100 m, 500 m, 1200 m or 2400 m. The shallower the range the better the depth resolution and accuracy.

    Originally designed for NASA

    The online CT was initially designed for use on NASA‘s micro-sub deployed in waters deep under the Antarctic glacier, exploring lifeforms deep under the glacier. Star-Oddi's CTD logger was chosen by NASA because of its small size and reliability.