ISO 16957:2016描述了一种测量湿多孔建筑材料热导率（扩散率）的方法和一种评估测量不确定度的方法。 虽然ISO 10051是当前的国际标准，但基于稳态方法，ISO 16957:2016提出了一种使用非稳态方法的方法，该方法使用短时间内的小温度变化作为输入。在进行测量的同时，还对测量不确定度进行了评估，这使得一种简单实用的测量方法成为可能。 ISO 16957:2016旨在测量表观（有效）导热系数，包括蒸汽运动引起的潜热传递。不包括由于对流或重力导致水分和/或空气流动的情况。ISO 16957:2016不适用于高含水量，因此可以忽略重力效应。 ISO 16957:2016可适用于重量超过约100 kg/m3的多孔材料，其中可以忽略辐射传热。 它规定了以下内容: a） 测量导热系数的非稳态方法； b） 由水分运动和不均匀水分分布引起的测量不确定度的近似公式（从而确定满足测量不确定度上限的测量条件）； c） 对水分（蒸汽）运动引起的热传递的估计。

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.