Ion is charge carrier, it will charge to the electrode surface. When the electrode surface is too small or ion concentration is too high, the charge exchange process cannot as soon as possible, on the surface of the electrode will form the ion cloud covered electrode. For direct current (dc), the initial current will gradually tend to be zero. Due to the conductivity measurement is used in the communication, it will only produce a limited additional resistance, the resistor is unwanted, of course.
The polarization effect can be diminished by the following methods:
1, for the corresponding conductance measurement range to choose the appropriate frequency.
2, choose suitable electrode constant (e.g., K = 1 and K = 10). The higher the conductivity value is, the greater the surface of the electrode or electrode distance between. Because of this, electrode current density will be kept in low level (typical values < 1 ma/cm2).
3, choose suitable electrode material and electrode surface treatment.
By adopting the above measures, cole's electrode can be used the occasion of 200 ms/cm.