Sensitivity Tunable Inductive Fluid Conductivity Sensor Based on RF Phase Detection

New results are presented for a sensitivity-tunable, inductive fluid conductivity sensor based on RF phase detection. An electronically controlled RF phase shifter allows the sensor to function in a wide range of conductivities from 2-70 mS/cm and helps tune the sensitivity of the response in a selected conductivity range. The noncontact nature of the sensor makes it suitable for corrosive fluids. Furthermore, the small size of the sensing element (1 inch. Sq X 6 mm thick) makes it suitable for compact in-line and hand held monitoring systems.