This apparatus is used to measure the deformation in elements of roof truss. Whenever a load is applied to a roof truss, its members undergo a strain.
This unit consists of a base structure which provides the support locations for the roof truss. Three metallic elements form a roof truss in a triangular shape. Load is applied from the top of the roof truss structure via a hanger. Each member has a dial gauge connected to it which shows the deformation produced due to applied load in each member.