On Using Strain Gauges in Electronic Assemblies When Temperature Is Not Constant

In a previous paper we presented this equation for processing strain gauge readings when the temperature is changing:^{E = E}gauge reading^-Eapparent strain^+Estandard material Second-order corrections to this equation are presented, and the size of the corrections and their uncertainties are estimated. Included are measurements on NBS standard reference materials (Cu and glass), which verify the accuracy of the method to within about +60 ppm (i.e., 60 microstrain) for the range -25° to + 125°C.