Development of Viscosity Measuring Device Using Vibrational Technique

The project centers on the development of viscosity measuring device using vibrational techniques. The instrument consists of a variable power supply, two solenoids each with plungers, needle with a pendulum bob attached, switching circuit, current – voltage sensors, microcontroller, analog–to–digital converter and Liquid Crystal Display (LCD) unit. The developed system consists of a variable power supply used to create varying magnetic fields in the solenoids so that the plungers can attract and release the pendulum bob. As the magnetic field strength varies, the pendulum experiences force sufficient to overcome the internal friction within the liquid. The pendulum bob is thus set into periodic to and fro motion. The pendulum bob movement was monitored by a microcontroller through a reflective optical sensor. Viscosity was measured through the calibration constant generated from a liquid of known viscosity, applied voltage, current generated from the solenoids and the dragging time. Gear oil, engine oil, palm oil, olive oil were the fluids investigated with the developed system for performance evaluation. Statistical analysis revealed a percentage error value of 2.87% and accuracy of 97.13% which shows a good agreement between the standard and what is available in the literature. The instrument performed well and it is therefore suitable for the measurement of liquids' viscosities.