A Sensing Device on Liquid Density

Abstract

This study presents a device, which can be used to detect density of various liquid. The device is composed of at least three buoys and a mechanism that is balanced by rotary moment. The design of the device presented in this study is based on the moment balanced position of the buoy on liquid. Designing parameters such as mass and volume of the buoys, relative angles of installation, and distance between the mass center and rotation center are adjustable. The device can be designed not only as a detector of liquid density but also a logic sensor of liquid density. The device will turn over and rotate 180o when density of the liquid reached some value, which can be preset in designing by adjusting relative parameters. The device has been practically tested that when the density of liquid changes from 1 g/cm3 to 0.933 g/cm3, the position of balanced angle changes about 90o. Turn over rotation occurs at the density of 0.933 g/cm3, which is about 2.8% of error from the designed value, 0.96 g/cm3. This device is proved to be feasible.