In the dry segment, use a black standard thermometer or a blackboard thermometer to measure the temperature of the sample surface.

If a black standard thermometer is used, it should be composed of a flat steel plate with a thickness of about 0.5mm, and its typical length and width dimensions are 70mm × 40mm. The surface of the board facing the radiation source should be coated with a coating that can absorb 90% to 95% of human radiation energy with a wavelength of up to 2500 nm. The coating has good resistance to talent. At the center far from the radiation source plate, there is a platinum temperature resistance sensor, which has good thermal contact with the plate. There is a 5mm thick polyvinylidene fluoride (PVDF) liner on the surface facing away from the radiation source. There is a small space in the PVDF haptics that is sufficient for platinum temperature resistance sensors. The distance between the sensor and the groove edge of the PVDF board is about 1 mm. The length and width of the PVDF plate should be large enough to ensure that there is no metal-to-metal thermal contact between the metal plate of the black standard thermometer and the bracket on which it is installed. The metal part of the bracket is at least 4 mm away from the edge of the metal plate of the black standard thermometer. It is permissible to use black standard thermometers of different structures, as long as all the steady-state temperature and irradiance setting conditions that can be reached by the exposure device are changed, the temperature indicated by the iron thermometer and the thermometer of the specified structure is related within ± 1 ℃ can. In addition, the time required for the structured black standard thermometer to reach a stable state must be within 10% of the time required for the structured black standard thermometer to reach a stable state.

If the xenon lamp weathering test box uses a blackboard thermometer, it should also be composed of a corrosion-resistant metal plate. Typical dimensions are 150mm long, 70mm wide and 1mm thick. Facing the obsolete panel is coated with black anti-aging coating. The coating should be able to absorb at least 90% to 95% of the radiation in 2500nm. A rod-shaped platinum thermocouple is fixed in the center of the plate facing the radiation source. The back of the metal plate should be exposed to the air inside the box.

If there is any change in the black surface of the xenon lamp weathering test box, the equipment manufacturer's instructions should be consulted.

Note 1: The difference between the black standard thermometer and the plate thermometer is that the former is fixed on an insulated bracket. The measured temperature is comparable to the temperature of the exposed sample surface coated with a black or dark coating on a low thermal conductivity substrate, and the exposed surface temperature of the light-colored coated sample is generally lower.

Note 2: The temperature of the test sample table depends on many factors, including the total amount of absorbed radiation, the total amount of emitted radiation, the thermal conductivity of the sample, the thermal conduction between the sample and the air, the thermal conduction between the sample and the sample frame And other factors. Therefore, the temperature of the sample surface cannot be accurately predicted.

Note 3: Under typical exposure test conditions (non-high irradiance test), the temperature measured by the black standard thermometer is about 5 ° C higher than that measured by the blackboard thermometer. Under high irradiance test conditions, the temperature difference between the two will increase.

Note 4: The black standard thermometer is also called adiabatic blackboard thermometer. Blackboard thermometers are also called non-adiabatic blackboard thermometers.

In order to measure the temperature range of the sample surface during the exposure process and better control the exposure conditions of the equipment, in addition to the black standard thermometer or blackboard thermometer, a white standard thermometer or whiteboard thermometer similar to the black mark or blackboard thermometer design is also It is recommended to use. For this purpose, an aging-resistant white coating is used, which reflects at least 90% of the radiation at a wavelength of 300 nm to 1000 nm and at least 60% of the radiation at a wavelength of 1000 nm to 200 nm.

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