Bar and Gauge Apparatus

This apparatus is designed for use in introducing aspects of the thermal expansion and cooling contraction of metals. The gauge has three features: a horizontal slot of length slightly greater than that of the metal rod, a circular hole with diameter slightly greater than that of the rod and a notch with width slightly less than the diameter of the rod. The first two features can be used to demonstrate that the dimensions of the rod, when it is heated, can exceed the dimensions of the (unheated) slot and circular hole. The third feature can be used to demonstrate that the notch, when the surrounding metal is heated, can be made to accommodate the diameter of the unheated rod.

A high temperature is required for sufficient expansion of the rod and/or the gauge (i.e. Bunsen burner. This apparatus should be used with a heat proof holder for the gauge and a heat proof surface to receive the heated components after use.