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The working principle of UV aging test chamber

The working principle of UV aging test chamber

The UV aging chamber is a light-based photoaging test device that simulates the ultraviolet light in the sun. At the same time it can reproduce the damage caused by rain and dew. The equipment is tested by passing the test material in a reciprocating cycle of controlled sunlight and moisture while increasing the temperature. The device uses an ultraviolet fluorescent lamp to simulate the sun, while also simulating moisture effects by condensation or spraying.

It takes only a few days or weeks, and the UV aging chamber can reproduce the outdoor months or years of destruction. Damage caused mainly includes fading, discoloration, brightness decline, pulverization, cracking, blurred, brittle, decreased strength and oxidation. The test data provided by the equipment is of great help in the selection of new materials, improvements in existing materials or assessment of changes in the durability of the product. The device can well guess the changes that the product will encounter in the outdoors.

Although UV (UV) only 5% of the sun, but it is caused by the decline in outdoor products, the main lighting factor. This is due to the increase in the photochemical reaction of the sun as the wavelength decreases. Therefore, it is not necessary to reproduce the entire solar spectrum when simulating the effect of sunlight on the destruction of the physical properties of the material. In most cases, only need to simulate shortwave UV light can be. The reason why UV lamps are used in UV aging chambers is that they are more stable than other lamps and are better able to reproduce the test results. The use of fluorescent UV lamp to simulate the impact of sunlight on the physical properties, such as brightness reduction, cracking, peeling, etc., is the best way. There are several different UV lamps available. Most of these UV lamps produce UV light instead of visible and infrared light. The main differences in the lamp are reflected in their differences in the total UV energy produced in their respective wavelength ranges. Different lights will produce different test results. Actual exposure to the application environment.

You can suggest which type of UV lamp should be selected.
 UVA-340, the best choice for simulating sunshine UV
UVA-340 can best simulate the critical short-wave wavelength range of the sun spectrum, that is, the wavelength range of 295-360nm spectrum, UVA-340 only in the sun can be found in the UV wavelength spectrum.
UVB-313 for maximum acceleration testing
UVB-313 can quickly provide test results. They use the short wavelength UV than the current Earth is usually found in the UV light is more intense. Although these are more non-natural than the natural wave of UV light to maximize the accelerated test, but it will also cause some material does not match and the actual degradation of damage.
 Standard definition of a light output below 300nm light energy is less than 2% of the total output of a fluorescent UV lamp, commonly known as UV-A light; launch 300nm below the light energy is greater than 10% of the total output of a fluorescent light , Commonly referred to as UV-B lamps;
UV-A wavelength range of 315-400nm; UV-B wavelength range of 280-315nm;

In the outdoor material and moisture contact time, up to 12 hours a day, the results show that the main cause of this outdoor wetting is dew, not rain. The UV aging chamber simulates the effects of outdoor moisture through a series of unique condensation principles. In the condensing cycle of the equipment, there is a water tank at the bottom of the tank and heated to produce water vapor. The hot steam maintains the relative humidity in the chamber at 100% and maintains a relatively high temperature. The design of the product ensures that the test specimen actually constitutes the side wall of the test chamber so that the back of the specimen is exposed to the ambient air. The cooling effect of the indoor air causes the surface temperature of the specimen to drop below the level of the steam temperature. The occurrence of this temperature caused the specimen throughout the condensation cycle, the surface of the liquid has always been condensed natural water. This condensed product is very stable pure distilled water. This pure water has improved the reproducibility of the test while avoiding the problem of water stains.
As the outdoor exposure to wet time can be up to 12 hours a day, so the UV aging test chamber
The wet cycle typically lasts for several hours. We recommend that each condensing cycle last for at least 4 hours. It is noted that the UV exposure and condensation exposure in the equipment are carried out separately from the actual weather conditions.

 For some applications, water spray can better simulate the ultimate use of environmental conditions. Water spray is extremely useful in simulating mechanical corrosion due to temperature upheaval and due to rainwater rinsing. UV aging testing machine / spray type is designed to reproduce this condition and specially designed.

As a result of frequent rinsing from rain, the coating layer of wood, including paint and colorants, will be the corresponding corrosion phenomenon. Recent studies have shown that this rainwater rinse action can rinse off the impermeable coating layer on the surface of the material, allowing the material itself to be exposed directly to the devastating effects of UV and moisture. This process can be repeated several times, resulting in a material degradation phenomenon, and alone can not reproduce the way of condensation.

The advantages of fluorescent lamps are: quick access to test results; simplified light intensity control; stable spectrum; only a small amount of maintenance; cheap, running with fairness.
 

Emma
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