A Conductivity Bridge for Measurement of the Salinity of Sea Water

Abstract : A sea-going conductivity bridge (Salinometer) for measuring the salinity of sea water is described in considerable detail. In principle, the salinity of an unknown sample is determined by comparing its conductivity with that of a sample of known salinity at the same temperature. The calibration of the bridge is found empirically. The instrument consists of a constant temperature bath, a 1000 cycle impedance bridge using glass conductivity cells in two of its arms, a phase detector to convert the 1000 cycles output of the bridge to DC and a balancing mechanism to complete automatically the 'fine' adjustment in bridge balance. It operates from a 110 v60 cycle power source. (Author)