A new high-frequency, nonfouling, four-electrode, open-cell conductivity sensor for oceanic use is proposed. This sensor is to replace the commonly used conductivity cell made by n. Brown instrument system. The new sensor will be designed to minimize or eliminate problems associated with n. Brown conductivity cell. Some stringent design criteria are set for the new conductivity sensor: 1. The sensor should be nonfouling for oceanic use. 2. It should be compatible to the existing Neil Brown electronics. 3. An open-cell, four electrode type is highly desirable. 4. It should have a spatial resolution of 0.5 cm or less. 5. It should possess an unbiased highfrequency response of at least 500 hertz. 6. It should be free from conductivity film effect or boundary-layer flow effect. A preliminary investigation has shown that the above criteria can be fulfilled by the proposed new conductivity sensor.
