A Steady-State Apparatus to Measure the Thermal Conductivity of Solids

This paper presents a steady-state apparatus to measure the thermal conductivity of solids based on the use of heat flux sensors. The uncertainty assessment of the experimental apparatus is performed in accordance with the ISO “Guide to the Expression of Uncertainty in Measurement” (GUM): the combined standard uncertainty (k = 1) with reference to the properties of Pyrex Glass CRM 039 at 20°C is ±1.9%. The standard uncertainty has also been assessed in the measurement range from 0.1 to 10W · m−1 · K−1. The experimental apparatus has been used to measure the certified reference material Pyrex Glass CRM 039 in the temperature range from 3.1 to 60.3°C: the standard deviation (k = 1) between the experimental measurements and the certified values is ±1.1% with a maximum deviation of 2.4%. Reasonable agreement is found between the uncertainty assessment and the experimental validation.