A sand control screen assembly comprises a base pipe having at least one opening that allows fluid flow therethrough and a filter medium positioned about the exterior of the base pipe that allows fluid flow therethrough and prevents particulate flow therethrough. Metal oxide or hydroxide with a rare earth oxide may be included in the cathode to improve the electrode capacity and shelf life. The list request is rebuilt in accordance with the completion of the sort routine. The wave length difference is selected according to a distance of two measuring areas which are arranged at a distance in the depth direction of the sample. In some embodiments, when the user receiver device receives signals from at least two spot beams, the user receiver device calculates the estimate of the location of the user receiver device to be located in the center of the intersection of at least two spot beams.