Artificial weathering test conditions for carbon arc lamps

The main factors that simulate the natural climate environment in the artificial climate accelerated aging test are sunlight, temperature, rainfall, humidity, etc. The artificial climate aging test generally simulates the above factors, of which sunlight is an important factor.

 

a. Irradiation intensity In the artificial weathering test, the irradiation amount of the light source is the main factor that determines the aging degree of the sample. The greater the irradiation amount, the more serious the aging degree. The radiation intensity is generally specified in the test methods of various countries. Among them, GB/T16422.2 stipulates that the wavelength of the passband between 290-800nm, the radiation intensity of 550w/m2 is selected as the reference value of the exposure test, usually The 340nm spectral irradiance intensity is 0.5w/m2·nm as the test irradiance intensity; while the commonly used irradiance intensity of ASTMG155 is 0.35w/m2·nm (340nm spectral irradiance intensity). During the test, the radiation intensity should be set according to the specific requirements.

 

b. Test temperature and humidity

 

(1) Test temperature Because the surface temperature of the sample is difficult to accurately measure, the black standard temperature is used as the test temperature. The black standard temperature is similar to the temperature of the dark sample with poor thermal conductivity. The black standard thermometer is placed on the sample holder and tested. It is irradiated by xenon lamp in the same way. There are 2 black standard temperatures for selection in GB/T16422.2: (65±3)℃, (100±3)℃, when the test temperature is high, the heat aging effect of the sample is enhanced, changing the artificial light-based The nature of the climate aging test, in the actual test, the commonly used temperature is (65±3)℃, and the commonly used temperature of AsTMG155 is 63℃. The black standard temperature is different from the temperature of the sample chamber. The former is higher than the latter. The temperature of the sample chamber is generally set to about 40℃. Generally speaking, the temperature of the sample is between the temperature of the sample chamber and the black standard temperature. between.

(2) Test humidity The humidity specified in GB/T16422.2 is (50±5)% and (65±5)%. In the actual test, (65±5)% is generally used as the humidity of the test, and there is no clear stipulation in ASTMC155 Humidity value.

 

(3) The rainfall in the rainfall cycle test simulates the real rainfall in the atmospheric environment. The rainfall causes the sample to be affected by the alternation of cold and heat, and can wash away the stains on the surface of the sample. Rainfall generally uses deionized water or distilled water to avoid corrosion of equipment. The rainfall cycle specified in GB/T16422.2 is: rainfall 18 minutes/rainfall interval 102 minutes. The common rainfall cycle of ASTMG155 is the same as GB/T16422.2.