Extreme-Condition Sensors for Use with Electrical Capacitance VolumeTomography & Capacitance Sensing Applications
A modular and non-invasive ECVT sensor that can be adapted and scaled to vessel demands.
Electrical Capacitance Volume Tomography (ECVT) is a non-invasive image reconstruction that provides volumetric images of a material. An ECVT system is generally comprised of a sensor, data acquisition system, computer system, and software for reconstruction of the 3D image. Capacitance data collected from the electrodes or plates placed around or near the region of interest are used to achieve the image reconstruction. In ECVT, sensor plates are generally distributed around the circumference or along the edge of a vessel under interrogation. If the plates are along the outside of the vessel, the vessel itself should not be an electrical conductor in order for the electric field to penetrate the region of interest. This presents a challenge in high pressure and high temperature applications, where such high-pressure high temperature vessels are usually made of steel or other electrical conductors.
Researchers at The Ohio State University, have developed a novel, non-invasive ECVT sensor that operates in harsh environments allowing for measurements of high pressure flow systems. The general design consists of capacitance plates arranged on the inner surface of a high-strength vessel held in place by bolts. This arrangement allows the force to be transmitted from the capacitance plates to the outer high-strength vessel. Each capacitance plate is electrically connected to a data collection unit via the bolt that affixes the capacitance plate. The capacitance plate is coated on the fluid side with a dielectric material which allows for the formation of a capacitor for ECVT measurements and can withstand high temperature, highly abrasive, and highly corrosive conditions. Examples of materials used for the coating include ceramics and high temperature plastics. The device has been designed to be entirely modular so that components are easily replaced.