Development of the Measurement Apparatus for the Effective Thermal Conductivity of Core Material

Abstract

A measurement apparatus is designed and fabricated to measure the effective thermal conductivity (k eff) of a VIP (vacuum insulation panel) core specimen under various vacuum states and external loads. The apparatus consists of part for measuring k eff, and parts for controlling external load and vacuum condition. Uncertainty of the apparatus is validated by measuring the standard reference material and comparing with commercial devices with VIP samples. Assessed uncertainty is maximum 2.5% in case of the standard reference material, 10% in case of VIP samples. Using the apparatus, k eff of glass paper under various vacuum levels is examined.