Acceptance method for thermal conductivity meter using thermal protection flat plate method
Please refer to the following suggestions for acceptance of the thermal conductivity meter using the thermal protection flat plate method. Only thermal conductivity meters that meet all of the following requirements are truly qualified instruments.
（1） Acceptance criteria:
1. Technical indicators: repeatability under the same measurement conditions; Temperature operating range.
2. GB/T 10294-2008 National Standard: Determination of steady-state thermal resistance and related characteristics of insulation materials.
3. The national or industry standards for measuring the thermal conductivity of different energy-saving insulation materials are attached.
（2） Key technology acceptance project
1. Acceptance of thermal conductivity measurement range:
(1) Upper limit of thermal conductivity: Choose materials as close as possible to 2.20 W/(m · K) (organic glass can be used, which has a thermal conductivity of about 1.0 W/(m · K) to detect the upper limit of the thermal conductivity measurement range;
(2) Lower limit of thermal conductivity: Choose materials with the smallest thermal conductivity possible (it is recommended to use vacuum insulation panels with a thermal conductivity of approximately 0.003 W/(m · K) as the lower limit of the thermal conductivity measurement range).
2. Acceptance of the influence of thickness on thermal conductivity: For the same type of tested material, changing the thickness of the specimen, such as from 20mm to 30mm, while keeping other measurement conditions unchanged, the measured thermal conductivity should be consistent.
3. Acceptance of the influence of temperature difference between cold and hot plates on thermal conductivity: For the same tested material, at the same average temperature (the average temperature of the cold and hot plates), such as 25 ℃, changing the temperature difference between the cold and hot plates, such as from 10 ℃ for the cold plate and 40 ℃ for the hot plate, to 20 ℃ for the cold plate and 30 ℃ for the hot plate, or 15 ℃ for the cold plate and 35 ℃ for the hot plate, the measured thermal conductivity should be consistent.
4. Acceptance of thermal conductivity temperature curve of standard substance: The thermal conductivity of the standard substance (standard plate) from the National Building Materials Institute is measured every 5 ℃ throughout the entire temperature range to obtain the thermal conductivity temperature curve, which is compared with the data provided by the standard substance itself.