New liquid electrical conductance measurement method based on pulsed excitation voltage

A new liquid electrical conductance measurement method based on pulsed excitation voltage is introduced in this paper. Using this method media polarization effects are eliminated. The complex and time-consuming amplifier, filter, signal conditioning and A/D converter are not needed, so the measurement circuitry is simplified and the measurement speed and accuracy are improved. The method can be used under the conditions of weak signal and high measurement speed. The characteristic of the measurement circuitry is the driving and sampling frequencies are equal, and digital data are measured directly. Experimental results show that the measurement resolution is better than 0.05% for the equivalent resistance range of 0.1-3 kΩ.