Figure 5.

Calibration of a sensor with air and water at different concentrations of KCl salt as references (black lines). (a) sensor conductivity against measurements by the conductivity-meter C931 of the firm Consort (Belgium); (b) sensor permittivity against water permittivity. At high conductivity, adjustments depend tightly on inductances of leads and electrodes, the latter being fixed. The last point is affected by bridge voltage $V_G$ exceeding 3.5 V; sensor sensitivity was $G_{eq}=24$ mS·V⁻¹.