Principles of Self-Temperature-Compensation Gages (SELCOM Gages)

The measuring object and the resistive element of the strain gage have linear expansion coefficients β_S and β_g , respectively. The strain gage bonded on the surface of the object provides a thermally-induced apparent strain ε T per 1°C that is expressed with the following equation:

Self-temperature-compensation strain gages are designed to adjust the resistive temperature coefficient of their resistive elements to match the linear expansion coeffcient of the measuring objects in order to get εT close to zero. When bonded to a suitable material, KYOWA's self-temperature-compensation gage (SELCOM gage) minimizes apparent strain in the compensated temperature range to ±1.8 μm/m/°C (Graph below shows apparent strain output of 3-wire strain gages).