Conductivity cell measurement method Conductivity Measurement principle: function and type

The measuring cell consists of two electrodes, an alternating voltage is applied to the electrodes, and the medium is in direct contact with the electrodes. The magnitude of the current generated by the applied voltage is related to the resistance of the medium (Ohm's law). The relationship between the geometric parameters (area S and distance d) of the measuring device and the constant K is: K = d/S.
The conductivity of the solution can be calculated from the known cell constant K and the measured current value.
In order to increase the measurement range of conductivity, measurement electrodes with different cell constants are used. The smaller the conductivity, the smaller the battery constant K of the selected electrode (see 6.4.2).
By selecting the cell constant, the conductivity method measures the conductivity of ultrapure water to the concentrate. The built-in PT 1000 temperature sensor is used for temperature compensation. If you want to measure the medium that will foul, you must periodically clean the electrode, otherwise it will affect the measurement.
K = 0.1 and
K = 1.0
K = 10
K = 0.01
Inductive measurement
The inductive conductivity cell includes two coils (primary and secondary). The two coils are located inside the probe and have a round hole at the end of the probe. The liquid surrounds the probe and is filled with round holes. A sinusoidal alternating voltage is applied to the primary coil, thereby producing a current in the liquid that is proportional to the conductivity of the liquid. This current in turn produces a voltage across the secondary coil, which is calculated by measuring the voltage and a known electrode constant. A built-in temperature sensor is used for temperature compensation.

Because inductive conductivity cells are isolated from the media, inductive measurements can be used for heavily contaminated media or corrosive media, but the probe housing must have a corresponding chemical impedance. Since the measuring electrode has a wide measuring range, electrodes of different cell constants are not required. However, inductive conductivity meters cannot measure very pure media because there is no measurement signal below a certain conductivity.