Design of a Contactless Electrical Impedance Measuring System for Removing Coupling Capacitance

In the process of fluid parameter detection, conductance detection technology has the advantages of simple structure and good response speed. However, this method belongs to contact measurement, there are some problems such as electrode polarization and corrosion, which affect the measurement accuracy. In the process of measurement, only the conductance of the impedance is extracted, and its imaginary part is ignored, so the impedance information of the fluid is not fully utilized. In the process of fluid detection, there will be coupling capacitors between electrode, tube wall and fluid, and the presence of coupling capacitors will cause measurement errors. Aiming at the above problems, a non-contact resistance measurement system based on fluid detection is designed which can eliminate coupling capacitance.