Research On The In-situ Resistivity Probe For Monitoring Erosion And Sedimentation Of Seabed

This study work aimed to design of a resistivity probe for in-situ monitoring the resuspension flux in storm surge which was based on the National High-tech Research and Development Program (863 Program, No. 2008AA09Z109).This paper focused on structure design of the resistivity probe, the choice of parameters of electrodes and the application of the probe for interface discrimination. Finally, the prototype was made with the optimum parameters.Firstly, the structure of the probe was designed and the related parameters were given. The electrodes array was equipped on the columned probe which its diameter and the thickness were 10mm and 70mm respectively. The material was Acrylic. For sealing compound, epoxy resin was chosen. And the steel structure supported the whole body. Secondly, the electrode parameters were investigated. The experiment results showed that the electrode shape and the space between them played a major role to the resistivity values. For sediment with ring electrodes, the resistivity was becoming smaller with the space increasing. And the measuring result is close to the value got by traditional methods. For seawater, the relation between electrodes'space and the resistivity value is quadratic function, and the R2 is 0.95. For sediment and seawater with dot electrodes measurement, the resistivity value had a linear relation with the electrodes'space. Some common materials which were used in electrodes were analyzed such as gold, silver, aluminum and brass. And the professional equipment for resistivity measurement was used to decide the size of the electrodes. Eventually, the optimum parameters were chosen as followed: ring electrodes; 10mm between electrodes; brass as the electrode material.Thirdly, the resistivity probe was applied to measure the interface of the sediment and seawater. The profile of the depth and the resistivity values was got from the instrument. Based on the resistivity distribution at the depth, the interface of different medium was recognized.The resistivity probe and its electrode parameters were design and tested. And this is the first time to achieve interface detection with our instrument in the lab. It can be used in harsh environment, and can monitor the erosion and sedimentation for a long time. So it must have a wide application range.