Chauvin Arnoux CSD 22 Notice De Fonctionnement page 23

3.2 CALIBRATING THE MEASUREMENT SYSTEM
In practice, the "cell constant" of the measurement line can be determined only by
calibration, by immersing the cell used in a standard solution having a known
conductivity at a given temperature (for example: decimolar aqueous solution of
potassium chloride).
Since the sensor provided has a cell constant close to one, a small adjustment
using the cell coefficient knob is sufficient to adjust the initial conductance reading
to the true conductivity of the reference solution (see tables of conductivity vs.
temperature).
The measurement system is then calibrated and gives a direct reading of the
conductivity of the medium studied.
3.3 DETERMINING THE CELL COEFFICIENT
However, if the user wants to determine the true cell constant of an insulated probe,
a pure resistance must be used.
First, the conductimeter connected to this pure resistance is adjusted. Then, the
probe, connected to the same adjusted instrument, is immersed in the reference
solution. The true cell constant of the probe is then found by calculating the ratio of
the conductance displayed to the known (measured) conductivity of this reference
solution.
G / γ = True cell constant
displayed reference
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