The Rheo-stick is a user-friendly visual viscosity comparator suitable for oils with a viscosity range from 32cSt to 680 cSt degrees C but it does not measure the physical viscosity of the oil in centistokes and cannot give an indication of the chemical composition of the oil nor identify specific contaminants nor degradation by-products. If a lubricant is too thin, the film may not be thick enough to prevent friction, creating unnecessary wear and tear. This results in unnecessary wear and tear on the components. If oil is too thick for the operating conditions, the machine is forced to work harder, thereby generating extra heat and using more energy. Viscosity is a property of significance as it effects tribological qualities such as friction and wear between interacting metal surfaces.” “The most important rheological property of a lubricant is its viscosity, or a fluid’s resistance to flow. “The Rheo-stick got its name from the word “rheology”, which is a branch of physics that deals with the study of the deformation – and specifically the flow – of matter, such as lubricating oils. Thick oil has a high viscosity, and thin oil has a low viscosity. Technical manager Steven Lumley, elaborates, “It is important to know the viscosity (thickness) of a lubricant because this determines its film strength and its efficiency in preventing friction between moving parts. Condition monitoring specialists, WearCheck, recently launched a quick, cost-effective viscosity test kit known as the WearCheck Rheo-stick.

Testing viscosity of oil