Testing the influence of temperature on mass at high temperatures

Special relativity predicts a very small influence of temperature on mass around ${\Delta}m/m{\approx}10^{-14}$. More than 100 years ago, experiments were performed that revealed limit $<10^{-8}$ for changes few degree at room temperature. A similar was obtained with magnetic suspension balance cryogenic temperatures. Recently, some measurements claim to have seen negative dependence the $10^{-6}$ level variety metal samples temperature, which would be interest e.g. explain variations in measurement gravitational constant. We an analytical vacuum and commercial thermogravimetric argon $3{\sigma}$ $<1.8 \times 10^{-8}$ both metallic (Cu, Pt) non-metallic (Al2O3) ranging from above $1000{\deg}C$. This extends previous high-temperature regime rules out all claimed anomalies by more two orders magnitude.