This is a concise description of the application of electrical tomography to measuring flows in pipelines and other industrial equipment. Tomographic instrumentation has been used since the 1950s for scanning the human body, but it is only in the last decade that cost-effective methods for industry have been developed. The principles of sensors and the image reconstruction techniques involved are all explained, making this book self-contained. Only a basic knowledge of instrumentation, electronics and computing systems is assumed, making this an accessible introduction for engineers just starting a research and development project, or students.