Gravesande ring with multimeter and thermos flask

Function

Intended for experimental study, physics laboratory, carrying out physics and natural science experiments on: Thermal expansion. The variation in volume and the variation in area of metallic bodies, as a function of temperature. What is meant by a Gravesande ring. The volumes of metallic bodies vary when their temperature changes. The areas of metallic bodies vary when their temperature changes. The dimensions of a hole in a metallic plate change when the plate is heated, etc.