A method and apparatus are provided to measure fluid resistivity. The method includes driving a first winding at a first frequency to induce a first current in a fluid present in a flow line and then driving the first winding at a second frequency to induce a second current in the fluid present in the flow line. The method includes measuring the first and second currents and based on these results, determining a resistivity of the fluid. The apparatus includes an apparatus usable with a well that includes a flow line and a first winding to circumscribe the flow line. Also included is a transmitter to induce a number of currents in the flow line and a second winding to provide signals used to derive representations of excitation voltages and current magnitudes. The apparatus may further include an engine to determine a resistivity of the fluid in the flow line.