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AAPS PharmSciTech. 2005 June; 6(2): E137–E143.
Published online 2005 September 30. doi:  10.1208/pt060221
PMCID: PMC2750524

An overview of electrical tomographic measurements in pharmaceutical and related application areas


Tomographic measurement techniques offer the opportunity to quantify the degree of homogeneity of particulate suspensions and other multiphase mixtures. Electrical resistance tomography is a relatively simple and inexpensive technique for measuring the distribution of electrical conductivity within multiphase systems. This can provide pertinent information about the physical form, the chemical composition, or the general status of manufacturing. In this contribution, we present recent applications of this technology to processes in pharmaceutical and related application areas. Examples include on-line measurement of solids distribution in stirred tanks and crystallizers, monitoring the performance of an industrial pressure filter, and flow profile and velocity measurements in a physical model of a catalytic reactor.

Keywords: tomography, process, electrical, mixing, crystallization

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
1. Williams RA, Beck MS. Process tomography: principles, techniques and applications. 7th ed. Oxford, UK: Butterworth-Heinemann; 1995.
2. Mann R, Dickin FJ, Wang M, et al. Application of electrical resistance tomography to interrogate mixing processes at plant scale. Chem Eng Sci. 1997;52:2087–2097. doi: 10.1016/S0009-2509(97)00036-5. [Cross Ref]
3. Vlaev D, Wang M, Dyakowski T, Mann R, Grieve BD. Detecting filter cake pathologies in solid-liquid filtration: semi-tech scale demonstration using electrical resistance tomography. Chem Eng J. 2000;77:87–92. doi: 10.1016/S1385-8947(99)00142-4. [Cross Ref]
4. Williams RA, Jia X, West RM, et al. Industrial monitoring of hydrocyclone operation using electrical resistance tomography. Miner Eng. 1999;12:1245–1252. doi: 10.1016/S0892-6875(99)00109-0. [Cross Ref]
5. Wang M, Jia X, Williams RA. Electrical tomographic imaging for bubble column measurement and control. In: McCann H, Scott DM, editors. Proceedings of SPIE, Volume: 4188. Bellingham, WA: SPIE; 2001. pp. 114–121.
6. Grieve BD, Dyakowski T, Mann R, Wang M. Interfacing, of EIT into an industrial pressure filter: a practical example.Proceedings of the 1st World Congress on Industrial Process Tomography, Buxton, UK, April 14–17, 1999.
7. Grieve BD, Smit Q, Mann R, York TA. The application of electrical resistance tomography to a large volume production pressure filter.Proceedings of the 2nd World Congress on Industrial Process Tomography, Hannover, Germany, August 29–31, 2001.
8. Grieve BD, Davidson JL, Mann R, Lionheart WRB, York T. Process compliant electrical impedance instrumentation for wide scale exploitation on industrial processes.Proceedings of the 3rdWorld Congress on Industrial Process Tomography, Banff, Canada, September 2–5, 2003.
9. Williams RA, Jia X, West RM, Roberts KJ. On line measurement of solids distributors in stirred tanks and crystallizers using electrical computed tomography.International Conference on Mixing and Crystallisation. April 22–25, 1998; Tioman Island, Malaysia.
10. Ricard F, Brechtelsbauer C, Lawrence C, Xu Y, Pannier A. Application of electrical resistance tomography to pharmaceutical processes. Can J Chem Eng. 2005;83(1):11–18. doi: 10.1002/cjce.5450830104. [Cross Ref]
11. Stanley SJ, Mann R, Primrose KM. Interrogation of a precipitation reaction by electrical resistance tomography. Am Inst Chem Eng J. 2005;51(2):607–614.
12. Bolton GT, Qiu CH, Wang M. A novel electrical tomography sensor for monitoring the phase distribution in industrial reactors.Fluid Mixing VII, July 10–11.
13. Fransolet E, Crine M, L’Homme G, Toye D, Marchot P. Analysis of electrical resistance tomography measurements obtained on a bubble column. Measure Sci Technol. 2001;12:1055–1060. doi: 10.1088/0957-0233/12/8/310. [Cross Ref]
14. Bolton GT, Hooper CW, Mann R, Stitt EH. Flow distribution and velocity measurement in a radial flow fixed bed reactor using electrical resistance tomography. Chem Eng Sci. 2004;59:1989–1997. doi: 10.1016/j.ces.2004.01.049. [Cross Ref]

Articles from AAPS PharmSciTech are provided here courtesy of American Association of Pharmaceutical Scientists