A fluid dynamic gauge (FDG) is a measurement technique used to study the behaviour of soft deposit layers in a liquid environment. It employs fluid mechanics to determine the thickness of the layer, and can also be used to obtain a measure of its strength. It was inspired by the technique of pneumatic gauging, which relies on a flow of air rather than the process liquid. Fluid dynamic gauging can be conducted as an in-line measuring technique, but is more commonly used as a research tool.
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The technique was originally developed to measure the buildup or removal of the fouling layers commonly encountered in the process industry (such as in the heat treatment of dairy products).[1] More recently, it has been applied to study cake buildup on porous membrane surfaces.[2] Scanning versions can determine the topology of a solid/soft-solid surface immersed in a liquid environment, in an analogous manner to an atomic force microscope, but exploiting the principles of fluid mechanics.[3]
Key features of the technique are that it can study soft deposit layers without touching them, relies on relatively simple operating principles, can be used in a completely opaque liquid, and does not rely on knowledge of the fluid or deposit properties.
References
edit- ^ Tuladhar, T. R.; Paterson, W. R.; Macleod, N.; Wilson, D. I. (2000). "Development of a novel non-contact thickness measurement technique for soft deposits and its application in fouling studies". The Canadian Journal of Chemical Engineering. 78 (5). Wiley: 935–947. doi:10.1002/cjce.5450780511.
- ^ Chew, Y. M. J.; Paterson, W. R.; Wilson, D. I. (2007). "Fluid Dynamic Gauging: A new tool to study deposition on porous surfaces". J. Membr. Sci. 296 (1–2). Elsevier: 29–41. doi:10.1016/j.memsci.2007.03.009.[dead link]
- ^ Gordon, P. W.; Brooker, A. D. W.; Chew, Y. M. J.; York, D. W.; Wilson, D. I. (2010). "A scanning fluid dynamic gauging technique for probing surface layers". Meas. Sci. Technol. 21 (8). IOP: 85–103. Bibcode:2010MeScT..21h5103G. doi:10.1088/0957-0233/21/8/085103. S2CID 121356281.