A high precision falling-ball viscometer using a fast camera

TL;DR

This paper presents a cost-effective, high-precision falling-ball viscometer using a high-speed camera, enabling accurate viscosity measurements suitable for educational settings and demonstrating excellent agreement with standard methods.

Contribution

It introduces a simple, inexpensive falling-ball viscometer with high precision using a high-speed camera, suitable for educational purposes.

Findings

Accurately measured glycerol viscosities matching standard techniques

Validated the method across different ball sizes and glycerol concentrations

Demonstrated suitability for undergraduate and high school laboratories

Abstract

This paper describes a simple and inexpensive method of measuring viscosity of a Newtonian fluid using the ball drop technique and an inexpensive point and shoot ~1000 frame per second camera. We successfully measured the viscosity of glycerol and glycerol-water mixture with high precision. We used three different size copper balls of diameters 0.8 mm, 1.59 mm, and 2.38 mm to check the accuracy of the measured viscosity in different concentrations of glycerol-water mixer solutions ranging from 50% to 100% (pure glycerol). Our measurements are in excellent agreement with the measurements conducted by other standard techniques. The simple and inexpensive techniques and physics we present in this manuscript can be employed to create a simple viscosity measurement setup for learning about complex fluid mechanics even at the undergraduate laboratory and high school teaching laboratory.