标准摘要
[中文适用范围]： 描述一种测量多孔材料热导率（扩散率）的方法和评估测量不确定度的方法。尽管ISO 10051随短时间输入而变化，但基于稳态方法的当前国际标准提出了使用非稳态方法来测量热导率，并利用小温度不确定性使得测量方法简单实用。本国际标准旨在测量材料表观（有效）热导率，包括由于水蒸气运动引起的潜热传递。排除因对流或重力导致水分和/或空气移动的情况。该国际标准不适用于高含湿量情况，因此可以忽略重力影响。本国际标准可应用于密度高于约100 kg/m³的多孔材料，在其中辐射传热可以忽略不计。 [外文原描述]： ISO 16957:2016 describes a method of measuring the thermal conductivity (diffusivity) of a wet porous building material and a method of evaluating the measurement uncertainty. While ISO 10051 is the current International Standard, based on a steady-state method, ISO 16957:2016 proposes a method that makes use of a non-steady-state method which uses a small temperature change with a short period as an input. Along with the measurement, an evaluation of the measurement uncertainty is described, which makes possible a simple and practical measuring method. ISO 16957:2016 intends to measure the apparent (effective) thermal conductivity, including latent heat transfer caused by vapour movement. The situation in which moisture and/or air movement occur due to convection or gravity is excluded. The application of ISO 16957:2016 to high moisture content is excluded so that the gravity effect can be neglected. ISO 16957:2016 can be applied to a porous material heavier than about 100 kg/m3, in which radiative heat transfer can be neglected. It specifies the following: a) a non-steady-state method of measuring thermal conductivity; b) an approximation formula for the measurement uncertainty caused by moisture movement and nonuniform moisture distribution (and, thus, a determination of the measuring conditions that satisfy the upper limit of measurement uncertainty); c) an estimate of the heat transfer caused by moisture (vapour) movement.
英文名称Measurement of apparent thermal conductivity of wet porous building materials by a periodic method