The thermal conductivity of liquid and gas-saturated glass sieves (frits) of porosities between 20 and 48 % is presented as measured at room temperature and ambient pressure. The saturating fluids cover a range in thermal conductivity from 0.018 W⋅m⁻¹⋅K⁻¹ to 0.598 W⋅m⁻¹⋅K⁻¹. The experimental results are fitted to a simple two-dimensional composite model for the heat transfer in porous media. The runs were carried out using a transient hot-bridge (THB) measuring instrument of an expanded uncertainty 3 % to 5 %. It turned out that (1) in order to correctly describe the experimental findings, a so-called thermal porosity has to be introduced that differs from the stated porosity of the frits. (2) There is not only a smaller-than-predicted thermal conductivity of gas-saturated frits as is known since a couple of decades but also a larger-than-predicted conductivity and, of course, a continuous transition between both effects. The whole latter effect can be attributed to the impact of dissolved He on the thermal conductivity of the matrix and be mathematically described in terms of the thermal porosity in the framework of the above-mentioned composite model.

在室温和环境压力下测得的液体和气体饱和玻璃筛（玻璃料）的孔隙率在20％至48％之间。饱和流体的导热系数范围从0.018W⋅m ^- 1⋅K ^-1到0.598W⋅m ^- 1⋅K ^-1。将实验结果拟合到用于多孔介质中传热的简单二维复合模型。运行使用瞬态热桥（THB）测量仪器进行，不确定性范围从3％扩展到5％。事实证明，（1）为了正确地描述实验结果，必须引入不同于玻璃料的规定孔隙率的所谓热孔隙率。（2）几十年来，不仅已知气体饱和玻璃料的导热系数比预期的要小，而且导热系数也比预期的要大，当然，这两种效应之间也存在连续的过渡。