A new liquid density measurement method based on elastic spring stretching

Abstract

A simple method is described for measuring liquid density based on stretching of the spring and equilibrium of weight and elastic force. The method involves placing a container with liquid under test on the spring causing a stretch of the spring that is directly proportional to the weight of the liquid. With this technique, the liquid density can be determined without measuring its mass and volume, and it should help students comprehend the concept of density more easily. The design of the measuring setup in this study is made using tools and materials that are simple and easy to obtain, such as spring, ruler, and small plastic or metallic container (tube). Two liquids used to test the measuring method were ethanol and glycerol. A test showed that the density of the test liquids at room temperature could be measured with the relative uncertainty of 3%, hence the reliability of the described method was confirmed.