The thermal output of a strain gage

The purpose of this article is to explain the causes of thermal output in strain gages and to show methods by which the effects can be minimized.

The purpose of this article is to explain the causes of thermal output in strain gages and to show methods by which the effects can be minimized. The physical relationship describing the effects of the thermal expansions of the test object and the measuring grid in combination with the temperature coefficient of resistance for the grid material are discussed.

The technique used by the manufacturer in producing temperature compensated strain gages is briefly explained on the basis of an "adjustment" of the strain gages' physical properties. Attention is also drawn to the effects produced by altering the length of the connection strips which are attached to some types of strain gage.