The GB/T 13475-2008 standard specifies a method for determining the steady-state heat transfer properties of thermal insulation materials using the calibrated and protective heat box method. This method is applicable to a variety of thermal insulation materials such as foam, rock wool and Glass wool, among others, and aims to evaluate the thermal insulation effect of these materials in practical applications. By measuring the heat transfer coefficient of materials under controlled temperature conditions, this standard provides a reliable means for measuring the Stability and Efficiency of thermal insulation performance of thermal insulation materials. Test results can be used for material design, selection and evaluation to ensure its application Reliability and performance conformity under various environment conditions.