Two types of high-temperature weldable strain gages: Ni−Cr half-bridge filaments and Pt−W half-bridge filaments

The historical development of the single active and “true” (zero gage factor) dummy weldable strain gage is reviewed. The combination of these devices into a half-bridge gage results in transducers capable of static-strain measurements at temperatures of 650 and 950° F for Ni?Cr alloy elements and Pt?W alloy elements, respectively. General application notes concerning these instruments are also included.