导热系数是保温材料最重要的热物理性能,对其进行准确的测试具有十分重要的意义。测试过程会受到方法及一些不可控因素的影响,因此测试结果的准确性需要被对比验证。本文以热流计法和防护热板法为例,对常用保温材料膨胀聚苯乙烯板(expanded polystyrene,EPS)的导热系数进行测定。实验采用不同厚度的试件进行测试。实验结果表明试件的热阻随试件的厚度的增加而线性增大;而导热系数作为材料的固有属性,也随厚度增加呈现上升趋势,说明了对测试结果进行修正的必要性。分析结果显示修正后材料的导热系数与试件厚度无关,通过2种方法得到的导热系数差异为2%,准确性较高。热流计法和防护热板法得到的测试导热系数与修正导热系数的最大差异分别为16%和25%,证明了测试中的系统性误差需要被考虑和修正。 Thermal conductivity is the most important thermophysical properties of insulation materials, and it is of great significance to conduct accurate tests on them. The test process will be affected by the method and some uncontrollable factors, so the accuracy of the test results need to be verified. In this paper, heat flow meter method and the protection of the hot plate method, for example, the commonly used thermal insulation material expanded polystyrene (expanded polystyrene, EPS) thermal conductivity was determined. Experiments using different thickness of the specimen for testing. The experimental results show that the thermal resistance increases linearly with the increase of specimen thickness, while the thermal conductivity as an intrinsic property of the material increases with the increase of thickness, indicating the necessity of correcting the test results. The results show that the thermal conductivity of the modified material has nothing to do with the thickness of the specimen. The difference of the thermal conductivity obtained by the two methods is 2%, and the accuracy is high. The maximum differences between the measured thermal conductivity and the corrected thermal conductivity obtained by the heat flow meter method and the protective hot plate method are 16% and 25%, respectively. This proves that the systematic errors in the test need to be considered and corrected.