Effect of Dimensions and Thermal Properties of Heat Flux Gage on Local Heat Flux Available to Purchase

Steady-state errors in the output in a thin foil-type heat flux gage have been calculated using conduction heat transfer analysis. These errors are a result of differences in the thermal properties and the geometry of the substrate and the gage. It was shown that the error in measuring steady state heat flux is affected by the ratio of the substrate to gage thickness ratio, substrate to gage thermal conductivity ratio, and the surface heat transfer coefficient. The amount of error varied between +40% to −20% for the cases considered. However, the errors were within 4% in most cases with a surface heat transfer coefficient was less than 10 W/m²K.