Description

Used to measure the linear expansion of a metal rod when subjected to heat, demonstrating thermal expansion principles. There are two legs made of cast metal that are connected by two plated metal rods. Each leg can support the ends of a 50-centimetre-long plated brass tube horizontally. The tube has an outlet in the middle with a holed rubber bung for inserting a thermometer to measure the temperature inside, as well as riffled nozzles at each end that can be used as steam inlets and outlets. The test rod is inserted in the brass tube supported in rubber bungs at its each end. A micrometre screw head with a reading of 0.0001 mm is attached to one end. On each leg, four-millimetre terminals are provided for connecting an electric bell or galvanometer to indicate whether contacts are made or broken. included three metal test rods, one made of copper, one of brass, and one of steel.