Fabrication and Electrical Characterization of XCP Electrode With Quasi-Nano Ag/AgCl Materials

Expendable current profilers (XCPs) have been employed for years to detect marine currents. However, the investigation of both the electric performance and the fabrication of XCP electrodes has been inadequate. In accordance with the moving measurement characteristics of XCPs, a fabrication method was developed for an XCP electrode with quasi-nano Ag/AgCl material, and a marine current simulation system was established for laboratory testing. The scanning electron microscopy results demonstrate that the AgCl particles in the electrode are smaller than 500 nm, which expands the contact areas for electrode materials. Furthermore, electrical characteristic results were obtained using the proposed current simulation system. The static electrical characteristic indicates that the electrode drift range is 6.7 nV/s. This performance is approximately 7.5 times better than the XCP requirement of 50 nV/s. The deviation for the additional electric field is
$0.4 \mu \text{V}$
/s. The dynamic electric property showed a relative error of 7% between the measured and the calculated electric field for a 5.14-cm/s current, proving that the test method is valid for XCP laboratory tests. This system for the dynamic electrical characteristic can also be applied to other current simulation experiments.