For accurately measuring the coefficient of linear expansion of electrically conducting materials such as metal rods.
Consists of a frame of thermally rigid material consisting of two cast end pieces connected by two steel rods which appropriately hold a plated brass pipe (l x d), 500 x 25mm. The pipe acts as a steam jacket and is fitted with steam inlet and outlets as well as a tube suitable for inserting a thermometer through a rubber stopper. The pipe jacket is held in proper alignment with the help of two metal yokes, requiring minimal adjustment while removing or inserting the rod under study. One of the yokes has a knurled thumb screw to lock the steam jacket in place.
The expanding rod makes contact with a 0.01mm micrometer which measures the extent of expansion when steam is passed through the jacket. The exact point of contact of the rod and the micrometer is found with the help of an indicator lamp. The design avoids use of loose wires.
Supplied with three rods of brass, copper and steel. Steam generator and thermometer are not included.