Remote conductivity sensor having transformer coupling in fluid flow path

A cell for remotely sensing conductivity of a fluid passing through it, said cell comprising

• fluid flow path means for defining a fluid flow path in a supply line, said means having an inlet and an outlet and two fluid paths between said inlet and outlet, thereby defining a fluid loop,
• an excitation transformer comprising a first toroidal core having a hole through it and wire turns around it, said core encompassing a portion of said fluid flow path means and said fluid loop therein, and
• a sensing transformer comprising a second torodial core having a hole through it and wire turns around it, said core encompassing a portion of said fluid flow path means and said fluid loop therein,
• said second toroidal core having a first plane of symmetry that is perpendicular to the axis of its hole, said first plane of symmetry being coplanar with a plane of symmetry of said first toroidal core that is perpendicular to the axis of its hole, to thereby reduce leakage coupling between said transformers,
• said fluid flow path means comprising two circular conduit portions having a first length, centers, and ends and two connecting portions connecting the ends of different said circular conduit portions of a second length measured between the centers of said two circular conduit portions, the outer diameter of each said conduit portion being approximately equal to the inner diameter of a said core and said wire turns on it, said first length being approximately equal to the thickness of a said core and said wire turns on it, said second length being approximately equal to the outer diameter of a said core and said wire turns on it.