Patent ID: 7696762

Claim:
An electrodeless conductivity sensor for determining conductivity of a process fluid, said sensor comprising: An electrically non-conductive conduit for the flow of a process fluid, said conduit having an inlet and an outlet; said conduit diverging downstream of the inlet into first and second legs, said legs re-converging upstream of said outlet, to form a fluid-flow loop between said inlet and said outlet; at least one first toroid configured as a first type coil disposed about one of said first and second legs; at least one second toroid configured as a second type coil disposed about one of said first and second legs; at least one third toroid configured as a redundant one of said first or second type coils disposed about one of said first and second legs; wherein coils of the same type are disposed on opposite legs, in co-planar orientation with one another; said first type and second type coils selected from the group consisting of drive and sense coils; at least one other sense coil disposed about said conduit outside of said fluid loop; and a connector configured to couple said first, second and third toroids to an analyzer.