What is Electrical Conductivity (EC).

EC or Electrical Conductivity of water is its ability to conduct an electric current. Salts or other chemicals that dissolve in water can break down into positively and negatively charged ions. These free ions in the water conduct electricity, so the water electrical conductivity depends on the concentration of ions.

Aquaread Electrical Conductivity Sensor

Aquaread’s electrical conductivity sensor utilises 4 stainless steel, gold coated rings ( as seen in the image below) to pass a current through a water sample to measure its resistance. The electrical conductivity of the water is the inverse of waters electrical resistance.

Using our EC sensor, you can measure the absolute conductivity (uncompensated), the conductivity compensated to 20 Degrees C or the conductivity compensated to 25 Degrees C (the European standard for conductivity measurement).

Electrical Conductivity

Key Features

  • Corrosion resistant gold coated stainless-steel build.
  • Smooth design reduces biofouling and dirt accumulation over time.
  • EC Measurement range: 0-200,000µS.
  • Single point calibration at one of the following concentrations:
    • 1413µS (adjustable to any value)
    • Rapidcal (2570µS)
    • SC-35 (an Aquaread solution that is NaCl based, set at 35ppt, designed for sea water applications)
  • Internal temperature compensation.
  • 3 Auto-range scales: 0 – 9999 µS/cm, 10.00 – 99.99 mS/cm, 100.0 – 200.0mS/cm.
  • Included on all multiparameter Aquaprobes and Aquasondes.
  • Easy maintenance.

Our EC sensors come as standard on many of our probes, below are some examples. To see all of the probes that feature EC please visit the Products section.



Portable, GPS AquaPlus Optical DO/EC system



Advanced portable multi-parameter Aquaprobe.


LeveLine CTD

Adds conductivity and salinity measurements

Always included

The conductivity sensor is included on every Aquaprobe and Aquasonde, it is also included in the AquaPlus optical dissolved oxygen sensor and our Leveline-CTD water level and conductivity logger. Its design is simple and robust and the sensor itself requires little maintenance to keep it operational.

Temperature and conductivity

Conductivity measurements vary with temperature, if the temperature increases so too does the conductivity measurement. This causes problems when performing monitoring as the readings fluctuate with both actual changes and temperature related changes.

In order allow comparison of conductivity results and remove the variation by temperature, the concept of a reference temperature was introduced. Generally, the reference temperature used is 25 Degrees Celsius (C), but sometimes the reference temperature of 20 degrees C is used.

All Aquaread conductivity sensors come pre-set to compensate at 25 degrees meaning you will not see any variation in your readings should the temperature of the water change during an event like rainfall. If this does not suit your application however, you are free to change this in the software.

Combined electrical conductivity and temperature

Because the relationship between conductivity and temperature are so important, our temperature sensor is located within the electrical conductivity sensor itself. Meaning you get an accurate compensation, quickly.