This standard is applicable to measurement of thermal conductivity of plastics by means of guarded hot plate (steady-state method), and is not applicable to measurement of plastics with a thermal conductivity greater than 2.20W/(m·K).
1 Definitions
1.1
thermal flux Φ
heat passing through a certain surface per unit time, in W
1.2
thermal flux density q
heat passing through unit area of a certain surface per unit time, in W/m2
1.3
thermal conductivity λ
heat passing through unit area per unit temperature gradient perpendicular to unit area under stable conditions, in W/(m·K)
2 Principle
2.1 This method is based on the principle of unidirectional steady heat conduction. Measure the heat passing through the effective heat transfer area of the test specimen, the temperature difference between the upper and lower surfaces of the test specimen, as well as the thicknesses of them when they are exposed to different stable temperatures, and then calculate the thermal conductivity accordingly.
