The QL40-OCEAN Idronaut Ocean Seven 310 probe combines a multi-parameter sensing unit manufactured by Idronaut srl, Brugherio, ITALY. This water quality probe is specifically designed for groundwater and environmental investigations. It uses reliable, accurate and drift-free high quality sensors and records a continuous profile of the borehole fluid properties.

In the standard configuration, the QL40-OCEAN probe is equipped with six sensors to measure: Pressure in dbar, Temperature in degrees C, Conductivity in µS/cm for fresh water or in mS/cm for salt water, Dissolved Oxygen in %, pH and Oxidation reduction (REDOX) potential in mV.

Full Schematic of QL40-OCEAN-310

In operation, the user can define the conductivity range for fresh or sea water environment and configure the tool processor for computing properties as: Conductivity corrected at 20°C and at 25°C, Fluid density, Salinity, Speed of sound, and O2 saturation in ppm. The QL40-OCEAN can be combined with other logging tools of the QL (Quick Link) product line or can be operated as a standalone tool.


  • Groundwater flows in open/cased holes
  • Borehole contamination studies
  • Advanced hydrochemical analysis
  • Salt-water intrusion studies
  • Location of water intervals of different quality
  • Water-well monitoring
  • Geothermal gradient logging

Operating Conditions

Borehole Fluid
[X] Water
[_] Mud
[_] Dry

[X] Uncased
[X] PVC Borehole
[X] Steel

[_] Required
[X] Non-Necessary

Features & Benefits

  • The only water quality tool of its kind that can collect detailed data at high pressures and temperatures.
  • Sensors can be used in a wide range of water types
  • Measurements are accurate and consistent.
  • Operates on any standard wireline (mono, 4 or 7 conductor, coax)
  • Slim, 40 mm diameter. One-person operation.

Specifications – Metric/English

Specification Metric Imperial
Diameter 40 mm 1.57 in.
Diameter at Sensor 43 mm 1.69 in.
Length 1.18 m 46.45 in.
Weight 4.5 Kg 9.8 lbs.
Measurement Point from bottom 0.15 m 5.9 in.
Temperature Range 0 – 50ºC 32 -122ºF
Max. Pressure 1500 dbar 2175 psi

OCEAN 310 Sensor Temp pH Conductivity O2 Redox

OCEAN 310 Sensor Temp pH Conductivity O2 Redox 2

Sensor Specifications

OCEAN 310 Sensor Ranges

(1) At 1 m/second flow rate.
(2) Other standard pressure transducers: 10, 40, 100, 200, 500, 1000, 2000 dbar.
(3) Differential pH preamplifier, 1013 ÷ 1014 ohm input impedance.
(4) Optional extended range, available upon request.
(5) Blue label membrane cap for profiling and monitoring.
(6) White label membrane cap for fast profiling.

Note: The QL40-OCEAN-310 does require frequent sensor maintenance and calibration. If maintenance is not performed, sensors may be permanently damaged and need to return to Italy for repair or replacement by Idronaut. Therefore, this probe is not recommended for those who cannot fulfill the maintenance requirement.

QL Stack Possibilities

  • QL40OCEAN + QL40GR (Gamma): Water-well Monitoring, Contaminant Intrusion Studies
  • QL40OCEAN + QL40GR (Gamma) + QL40DEV (Deviation): Identification of Aquifers correlated with well path.
  • QL40OCEAN + QL40GR (Gamma) + QL40ELOG (Resistivity): Hydrogeologist’s Tool, Groundwater exploration, assessment, and well completion


QL40-OCEAN Water Quality Brochure
User Guide
Idronaut User Guide

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