Scientifically, viscosity is the property of a fluid that causes it to resist flow.įor materials that flow, either while being processed (for pumping, spraying or coating) or in an end-use (like shampoo, detergent or paint), it is important to think about the material’s flow characteristics or viscosity. Most engineers know what viscosity is, but may have trouble explaining it or even understanding the full implications of the measured number. It is generally not a subject that is covered in much detail in many engineering curricula. Viscosity is a property that is often considered by process engineers, but seldom completely understood. Let’s first discuss the subject of viscosity. This article presents the applications for inline viscosity measurement and the means by which they are achieved.
While it is difficult to control all factors in the process that can affect a fluid’s viscosity (such as temperature, air bubbles, shear history, turbulence and so on), if these factors are kept relatively constant, then good control can be achieved. Inline viscosity measurements can give continuous, realtime readings of a fluid’s viscosity during processing and consequently, can provide a means to automate the viscosity control of process fluids.
