US Patent 6995563 Nonmetallic process connection

A sensor includes primary and secondary toroids disposed in spaced, coaxial relation to one another with a process flow path extending therethrough. Electrically conductive and non-metallic connectors are located at opposite ends of the flow path to physically contact the process fluid flowing therethrough. The primary toroid is configured to induce an electric current in the process fluid as the process fluid passes through the flow path, wherein the current varies with conductivity of the process fluid. The secondary toroid is configured to detect the electric current in the process fluid as the process fluid passes through the flow path, the current being proportional to the conductivity of the process fluid.