The Decagon CTD-10 sensor is a low cost, accurate tool for monitoring of water level, electrical conductivity, and temperature in both ground water and surface water.  The sensor utilizes a vented pressure transducer to obtain accurate water level measurements from 0 to 10 m while removing the effects of barometric pressure.  With a range of 0 to 120 dS/m, the CTD sensor has the ability to make accurate electrical conductivity measurements in a broad range of applications.


Decagon's CTD sensor is a robust, marine grade sensor, 3.4 cm in diameter. It connects by cable to an external datalogger. Much of the complex circuitry is in the data logger, lowering the cost of individual sensors without impacting their accuracy or resolution.  This makes it so that instead having to rely on a single measurement, you can measure in several different locations without exceeding your budget.


The CTD sensor is compatible with all Decagon Em50 series and Campbell Scientific data loggers. The Em50G offers a remote transmission option to deliver data wirelessly to your desktop. With this option, water depth, temperature, and electrical conductivity can be monitored from any internet-connected computer in near-real time.



  • Aquifer recharge and recovery.
  • Saltwater intrusion, desalination, and wastewater.
  • Wetland monitoring. 
  • Groundwater contamination monitoring.
  • Surface water monitoring.



  • Robust marine-grade epoxy overmold to resist corrosion in tough environments.
  • Compact 3.4 cm diameter sensor body to fit into tight spaces.
  • External logger with remote transmission option to deliver data to your desktop.
  • Permanent connection allows you to collect data continously without pulling up the sensor.
  • Low per-sensor cost.


Water Depth: 0 to 10,000 mm 

Electrical Conductivity: 0 to 120 dS/m

Temperature: -11 to 49 °C, do not expose to temperatures <32 °F if sensor is in water


Water Depth: 2 mm 

Electrical Conductivity: 0.001 dS/m

Temperature: 0.1°C


Water Depth: + 0.05% of full scale @ 20 °C

Electrical Conductivity: ±0.01 dS/m or ±10% (whichever is greater)

Temperature: ±1 °C

OPERATING TEMPERATURE 0° to 50°C (Pressure transducer cannot be allowed to freeze while submersed.)
POWER REQUIREMENTS 3.6 - 15 VDC, 0.03 mA quiescent, 0.5 mA during 300 ms measurement
DIMENSIONS 9 cm (l) x 3.4 cm (w)
MEASUREMENT TIME 300 ms (milliseconds)
OUTPUT Serial TTL, 3.6 Volts Levels or SDI-12
CONNECTOR TYPES 3.5 mm (stereo) plug, or stripped & tinned lead wires (3)
CABLE LENGTH 10 m standard; custom lengths available upon request
DATA LOGGER COMPATIBILITY (NOT EXCLUSIVE) Decagon Em50 Series, ProCheck, Campbell Scientific
SOFTWARE COMPATIBILITY ECH2O Utility (rev 1.64+), DataTrac3 (rev 3.4+)


Request Support

Email: support@decagon.com
Phone: 509-332-2756
Fax: 509-332-5158