Electrical Process Tomography

Electrical Tomography is a measurement technique for obtaining information about the contents of process vessels and pipelines. Multiple electrodes are arranged around the boundary of the vessel at fixed locations in such a way that they do not affect the flow or movement of materials. Tomographic measurement techniques differ from point measurement techniques, because they sample a substantial proportion of the process volume rather than at a single point. Circular pipeline-based sensors measure an entire cross-sectional volume. 

The technology can be used for liquid/liquid, solid/ liquid, gas/liquid, gas/solid/liquid systems. The spatial resolution of the imaging method and the sensitivity of the method depend specifically on the electrical properties of the system being measured and upon the dimensions of the process.

Typically, a sensor consists of 16 electrodes and for research applications up to 8 x 16 electrodes may be arranged within a process vessel.

The technique can be used with a wide range of research and development applications demonstrated, including:
1. interrogation of mixing processes 
2. investigating a solid-liquid filtration process 
3. monitoring the performance of a hydrocyclone 
4. measurement and control of bubble columns 
5. measurement of multiphase flow 

One of the main application areas of electrical tomography is the measurement of multiphase flow regimes.

Flow processes may involve a variety of phases or components in the gas, liquid or solid phase and are complex in their nature. Electrical tomography techniques provide the capability for flow visualisation, regardless of material opacity, to enhance the understanding of such complex flow processes.