Mobile Phone Enabled Pervasive Measurement of Liquid Viscosity

Viscosity is an intrinsic property of a fluid caused by friction between its own molecules layer while flowing. It would not only offer a decisive effect on the motion characteristics of the fluid, but also affects its application scopes. As a result, quickly and accurately understanding the physical feature of a fluid has always been an important target [1]. So far, the viscometers, the instrument used to measure the viscosity can generally be grouped into three broad categories [1, 2]: capillary tube viscometers [3], rotating viscometers [4], and falling ball viscometers [5]. However, structures for these conventional viscometers are generally complex and their operations appear somewhat difficult, which may significantly restrict their applications. Abstract: A new conceptual non-contact method for liquid viscosity measurement in capillary tube using mobile phone as the data acquisition facility is proposed. The video and image for the capillary force driven flow of the test liquid was recorded by the phone camera. After the imaging reconstruction of the flow velocity in the horizontal capillary and the capillary head in the vertical direction, a digital image processing software was developed to calculate the liquid viscosity in MATLAB 2007b environment, recurring to the established theoretical correlation for flow mechanics. To demonstrate the feasibility and accuracy of the method, 10 groups of liquid were measured and the results were compared with the data obtained from a standard rotating viscometer. The relative error was found falling in the range of 0 ~ 20 %. This study establishes a pervasive low cost way for viscosity measurement of various solutions.