Pro-Oceanus: GTD-Pro™ Submersible Sensor

The most accurate sensor in the world for measuring total dissolved gas pressure in studies of gas build-up, air-sea gas flux, and net biological production.

The GTD-Pro™ is the most accurate and stable total dissolved gas sensor on the market. It measures the sum of the partial pressures of all dissolved gases, i.e. gas tension.

In most natural waters N2 and O2 are the dominant dissolved gases. When oxygen is measured independently, N2 can be determined from gas tension. These gases measured together can be used to make substantially improved estimates of net biological production.

Additionally, gas tension measurements are used to study air-sea gas exchange and upper-ocean physical, chemical, and biological processes.

Also available is the HGTD-Pro™ hurricane model that uses a patented supported tubular interface for faster equilibration than the GTD-Pro™.


  • – High accuracy, long-term stability
  • – Multiple data outputs
  • – Superior response rate with the hurricane model, HGTD
  • – Easily integrated into any system
  • – Patented tubular interface (HGTD provides unique biofouling resistance)
  • – Internal data logger and controller with 2GB flash memory

pCO2 Sensor Applications

  • – Air-sea gas transfer rates
  • – Net biological production estimates
  • – Near-surface flux studies
  • – Correction of other dissolved gas measurements


Sensor Performance
Resolution0.002 mbar
Stability< 0.02 mbar/yr drift
Range (other ranges available)800-2000 mbar
Equilibration time (t63)GTD-Pro: 3 min
HGTD: 1 min
Length38 cm25.4 cm
Diameter10 cm11.7 cm
Weight air2.8 kg1.6 kg
Weight water0 kg0.6 kg
HousingAcetal Plastic
Depth0-600 m0-50 m
Input voltage10-30 VDC
Power consumption0.55 W
Data outputRS-232, ASCII format
Sample rate1 second (user selectable with datalogger/controller)

Telemetry2U Compatible

Telemetry2U lets you monitor your sensors, control devices and automate tasks – all through one simple, secure, and configurable IoT platform. Pro-Oceanus products are compatible with their technology, allowing for:

  • – Real-time data access on any device
  • – Alerts and alarms for parameters you define
  • –  Comprehensive reporting and historic data visualizations available on customizable dashboards

Servicing, Calibration and Support

Imbros’ local engineering department can service, repair and calibrate your instrument without expensive shipping costs or wait times.


More information from Pro-Oceanus Download Datasheet

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