1. Hot Wire Method (ASTM D5470)
The hot wire method is a classic method for measuring the thermal conductivity of materials. The principle is to insert a heated thin metal wire (hot wire) into the material to be tested, and calculate the thermal conductivity of the material by monitoring the temperature change during the hot wire heating process and the response of the surrounding materials. This method has the advantages of fast testing speed and wide application range, and is particularly suitable for materials with medium and low thermal conductivity. However, for materials with high thermal conductivity or large differences in anisotropic thermal conductivity, the accuracy of the hot wire method may be affected to a certain extent.
2. Guarded Hot Plate Method (GB/T 10294)
The guarded hot plate method is a more accurate steady-state test method. This method constructs a test system consisting of a heat source, a test piece, a cold source and a protective layer, measures the heat transfer through the test piece in a stable state, and then calculates the thermal conductivity. The guarded hot plate method can effectively avoid the influence of thermal radiation and convection on the test results, and is suitable for testing materials with various thermal conductivities.
3. Other methods
In addition to the hot wire method and the guarded hot plate method, there are other methods that can measure the thermal conductivity of silicone, such as the hot disk method and the laser flash method. These methods have their own characteristics, and the appropriate method can be selected for testing according to specific needs and experimental conditions.
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