A Coefficient Of Friction Tester is a tool used to measure the friction between two surfaces, typically a solid and a liquid or two solids. The coefficient of friction is a dimensionless number that represents the ratio of the force of friction between two surfaces to the normal force pressing them together.

The coefficient of friction tester typically consists of a load cell or force sensor, a mechanism to apply a normal force to the surfaces, and a device to measure the force of friction. Some testers may also include a mechanism to vary the speed or distance of the surfaces in contact with each other.

The coefficient of friction tester is used in a variety of industries, including materials science, manufacturing, and packaging, where it is important to understand the friction properties of materials. It is also used in product design, to ensure that the product surface friction is suitable for its intended use, for example, a packaging material that should be easy to open.