Abstract: A sensor for measuring ocean water salinity is described. The sensor may include a measurement clock circuit, a control clock circuit, and a comparator circuit. The measurement clock circuit, having an output that varies with salinity of a fluid, may have a first circuit architecture that includes a capacitive gap assembly that permits a fluid to flow into a gap between two electrodes of the capacitive gap assembly. The control clock circuit, having an output that does not vary with salinity of the fluid, may have a second circuit architecture comprising a capacitor. The comparator circuit may be configured to compare the controlled clock output to the measured clock output over a duration of time to determine a salinity measurement of the fluid.