An integrated ECT/ERT dual modality sensor

摘要

Capacitance and resistance tomography systems have been developed for visualizing the distributions of materials in an industrial process. They offer certain advantages over other tomography modalities, such as low cost, rapid response, no radiation and being non-intrusive. Single modal tomography could provide a satisfactory solution in most process applications. However, in some more complex applications, additional information is required for comprehensive understanding of the process under investigation. ECT and ERT are two most researched electrical tomography techniques. Individual ECT and ERT systems has been combined for dual modal measurement in recent years, however, the two sensors were located at two different cross-sections of the process, resulting in poor sensor integration and data fusion. As a result of the present research an integrated tomography system with capacitive and resistive sensors located at the same cross-section of the process has been developed. In the integrated system the use of both resistive and capacitive electrodes help eliminate mutual interferences between the two modalities. Experimental work with water-gas two-phase flow on vertical and horizontal pipes shows that the integrated system can provide effective dual modal measurements. The reconstructed images together with the stacked images are used to deduce such process parameters as gas holdup and flow velocity.