Figure 6.13 A conductivity cell. Current flows through the seawater between platinum electrodes in a cylinder of borosilicate glass 191mm long with an inside diameter between the electrodes of 4mm. The electric field lines (solid lines) are confined to the interior of the cell in this design making the measured conductivity (and instrument calibration) independent of objects near the cell. This is the cell used to measure conductivity and salinity shown in Figure 6.15. From Sea-Bird Electronics.