Factors affecting the test results of the lightfastness tester

Clothing, paint, plastic, rubber and other textile materials are often exposed to natural climate conditions, and their physical and chemical properties will inevitably change due to the combined effects of sun, rain, cold and heat, known as aging. Once a material has aged, its relevant performance will decline sharply. The results of material aging tests are usually influenced by the following three aspects.

Temperature in the chamber:
Aiming at the air-cooled xenon lamp, when it emits light, the emitted heat enters the test chamber through radiation and conduction, resulting in As the temperature rises , especially in the late phase of the lamp life, the heating part rises sharply, while the luminous part falls sharply. To ensure the stability of the light intensity, the power of the lamp had to be increased, making the lamp moregenerated heat. If you do not take appropriate measures, the temperature in the warehouse will inevitably remain high. At present, Freon cooling technology is basically used to cool the air in the warehouse. The principle is similar to the temperature and humidity control principle of the constant temperature and humidity laboratory, to ensure a certain temperature range.

Black panel temperature:
According to the different construction principles, it can be divided into black panel thermometer (BPT) and black panel temperature (BST). It is a comprehensive and intuitive expression of the light and heat energy received by the sample. After aging the xenon lamp, the light output is greatly reduced. In order to achieve the same level of fading, more testing time needs to be extended, and the proportion of heat generation has increased significantly; in combination with the obsolescence of the filter, the ability to filter infrared rays is decreased, resulting in a significant increase in BST and BPT. Therefore, the control of the temperature of the blackboard should be based on the warehouse ambient temperature, xenon lamp, filter, wind speed, etc., to effectively control the temperature of the board, to meet the requirements of various standards for the instrument. At the same time, it is also an important basis for judging whether the xenon lamp and filter are invalid.

Illumination intensity:
Long-arc xenon lamp is known as the most suitable artificial light source for sunlight spectrum simulation, with high power (greatly shortening the test cycle), anti-interference Strong, long longevity, low cost and many other advantages, so it is the best artificial light source It is divided into air-cooled type, such as Heraeus 150, 150S, 150S+ in West Germany, Q-SUN in the United States, Meccaso in Italy and Helios and other brands. There are water-cooled types such as: ATLAS, Ci3000+, Ci4000+, Ci5000+, etc.). Of course, in terms of cooling effect, the water-cooled type is better, but the air-cooled type has a great advantage of low cost because of its low cost.

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