E L S E V I E R Powder Technology 89 (1996) 87

POWDER TECHNOLOGY

Book Review

Imaging Industrial Flows - Applications of Electrical Process Tomography

Edited by A. Plaskowski, M.S. Beck, R. Thorn and T, Dyakowski, published by Institute of Physics Publishing, Brislot, UK, 214 pp, £60.00, ISBN 0-7503-0296-8

The term "process tomography' was, as far as I am aware, first coined by Professor Maurice Beck during the late 1980's. After around 10 years of work the authors believe that the time is ripe for a book on the subject, and I agree with that premise. The book is largely based on the work of the authors and many of their research students in the process tomogra- phy unit at UMIST, and so has a personal touch as well being technically sound.

The introduction offers a very clear guide on the book and how to use it, and the first chapter takes the reader through the state of the art in flow metering and the limitations that lead to the need for something more flow imaging. The use of the technique started as an attempt to take medical tomog- raphy systems and use them on industrial processes, but as the book amply demonstrates, the application now has a life of its own with the need for low cost, robust and last response systems. There is also a need for interpretation to give numer- ical results a far cry from the early pictorial medical appli- cations. These first two section of the book leave the reader well set to decide how to use the book to best advantage, always a helpful start. Page 15 has one of two typographical errors I found, where the phrase "Nuclear Magnetic Reso-

nance" is repeated (the other is on page 190 where "publications per head" should read 'per year').

The book then progresses strongly through the theory of two-component flow, the possible sensor systems, image reconstruction algorithms, image presentation and filtering and accuracy considerations. I particularly like the use of detailed case studies in the book which take it beyond being a dry text-book and into the subtleties of designing complex measurement systems from computer-aided design of the sen- sor through to the use of image bugs to derive the Freeman chain description of an object. The main techniques covered in depth are electrical impedance tomography (capacitance and resistance) and ultrasonics, but most other types get a least a mention to put them in perspective.

My only criticism is that the chapter on two-component flows is perhaps too detailed. That is not to say the chapter is not good; it is well written but simply a little out of balance with the rest. Otherwise, despite being a small book of 24 × 16 cm and 214 pages, the book successfully covers the subject in depth, is enjoyable to read and is undoubtedly authoritative. The last chapter of crystal-ball gazing is thought provoking, and leaves me in no doubt that the subject is in the critical phase of needing to prove that it has the power to change the measurement and control of industrial processes. The authors clearly feel that it can do precisely that.

Professor Andrew Hunt Schlumberger-Dowell,

Clamart, France

Elsevier Science S.A,