Measurements of internal heat transfer in germanium resistance thermometers

Heat transfer processes through the solid materials and the filling gas in germanium resistance thermometers from three manufacturers have been investigated experimentally at temperatures from 4.2 to 120 K. The experimental results agree with a published theoretical analysis. The heat transfer coefficient for these thermometers is found to vary by a factor of 50 for different types and different temperatures. In some thermometers, conduction through the gas is greater than that through the solid leads and the influence of contamination of the gas at temperatures between 45 and 65 K is very significant. However, in other thermometers solid conduction is the dominant heat transfer mechanism. It is suggested that solid conduction should be enhanced in the design of germanium resistance thermometers for use in the liquid‐nitrogen temperature range.