A Novel Needle Probe Based on High-Speed Complex Permittivity Measurements for Investigation of Dynamic Fluid Flows

For the investigation of multiphase or multicomponent flows, which are of interest, for instance, in oil extraction and processing or in chemical engineering, there are only few suitable measuring techniques. For this reason, we have developed a high-speed complex permittivity needle probe. Such probes are able to distinguish the different phases or components of a flow by measuring the complex value of the electrical permittivity at a high data rate (up to 20 000 samples/s). The performance of the system, as well as its ability to differentiate organic substances, has been analyzed. A time-resolved experiment in an oil-water-gas flow, as well as a two-substance mixing experiment in a stirred tank, is presented.