On the other hand, positive displacement flowmeters, such as Titan’s Oval Gear flow meters, operate effectively with higher viscosity liquids. The accuracy of the oval gear flowmeter depends on the liquid’s viscosity and the higher the viscosity, the better the range and accuracy. The reason behind this is to do with fluid slippage between the gears and pipe walls. As the viscosity of the liquid increases, fluid slippage quickly drops and a higher accuracy of measurement is achieved.
Other parameters will also affect the choice of flow meter in an application and Titan’s technical article explains the factors that determine flow meter performance in more detail.