GB/T 5990-2021 Active

This document describes the test methods for determining the thermal conductivity of refractory materials using the cross-hot-wire method and the parallel-hot-wire method, as well as the thermal diffusion coefficient and specific heat capacity of refractory materials.
The cross-hot-wire method is suitable for measuring the thermal conductivity of carbon-free refractory materials with a temperature not exceeding 1,250°C, a thermal conductivity less than 1.5 W/(m·K), and a thermal diffusion coefficient not exceeding 5×10-6 m2/s.
The parallel-hot-wire method is suitable for measuring the thermal conductivity of non-conductive refractory materials with a temperature not exceeding 1,250°C and a thermal conductivity less than 25 W/(m·K).
This document is also applicable to powdered and granular refractory materials.
Note 1: For the thermal conductivity of non-fired bricks and non-shaped refractory precast products, due to the influence of the dehydration of residual water after hardening or solidification during heating, the samples can be pretreated. The details of the pretreatment method, degree, and the insulation time of the samples during measurement are beyond the scope of this document and shall be agreed upon by both parties.
Note 2: Measuring non-homogeneous materials is generally difficult, especially for materials containing fibers. The measurement of such materials using this method shall be agreed upon by both parties.