Background: Thermal output of high temperature strain gauges can be measured by different methods.Purpose: This paper is to discover measurement methods’ effects on thermal output of high temperature strain gauge and to suggest a method of clamping instead of welding for fixture of high temperature strain gauge for thermal output measurement.Methods: By analysis of impacting factors of thermal output

thermal outputs were explored for mismatching thermal expansion coefficients between material of components to be tested and that of strain gauge base.Thermal outputs of all kinds by different fixture methods were obtained and compared for hanging

clamping and spot welding

respectively.Results: Thermal output obtained by way of hanging strain gauge can be used in case of installation on material of the same thermal expansion coefficient as the strain gauge base.And this hanging measurement method provides access to thermal output that strain gauge undergoes different temperature changing ratio from that one of provision offered by strain gauge fabrication factory.Thermal output obtained by way of clamping measurement method can substitute for the one obtained by spot welding.This clamping measurement method can not only realize the effect of spot welding

reducing calibration cost due to spot welding of strain gauges

but also realize the aim of calibration of strain gauges one by one with the strain gauges be intact after calibration.Differences between thermal outputs by two measurement ways of both hanging and clamping explain that large divergence can be made when thermal expansion coefficients between the material of strain gauge base and the one of the component to be installed on.Conclusions: Thermal output can be measured among all methods by fixture of clamping instead of welding

with an advantage of realizing strain gauge calibration one by one and also with a high precision.