Fiber Optic Capillary Flow Viscometer

When a liquid sample emerging out of a capillary tube under a laminar flow is collected in a container, the quantity of the collected sample increases with the time of liquid flow, but the rate of increment reduces when the liquid sample has higher viscosity. In the proposed viscometer, a fiber optic sensor converts increase in weight of the collected sample into a proportional DC voltage. Then, a data acquisition system estimates the viscosity of the liquid sample in terms of the rate at which sensor output voltage increases with the time of liquid flow. The remarkable features of the proposed viscometer include shorter measurement time, ease of implementation, and the potential ability to work with different types of Newtonian liquids.