How to use the UV chamber to do the UV aging test

The UV chamber is also knowm as the UV aging chamber is mainly used to simulate the destructive effects of sunlight, humidity, and temperature on materials. The ultraviolet aging chamber simulates sunlight, condensation, and natural humidity. The sample is tested in a simulated environment for a few days or weeks, which can reproduce the damage that may occur outdoors for several months or years.

The principle of UV aging chamber:
The damage of natural sunlight and moisture to materials causes incalculable economic losses every year. UV aging chambers can reproduce the damage caused by sunlight, rainwater, and dew. The device conducts the experiment by exposing the material to sunlight and placing it in a controlled interactive cycle of sunlight and moisture, while increasing the temperature.

The device uses ultraviolet fluorescent lamps to simulate sunlight, and can also simulate the influence of moisture through condensation or spraying. In just a few days or weeks, the device can reproduce the damage that takes months or years outdoors. The damage caused mainly includes fading, discoloration, decreased brightness, powdering, cracking, blurring, embrittlement, decreased strength, and oxidation. The test data provided by the equipment is of great help in selecting new materials, improving existing materials, or evaluating changes in the composition that affect product durability. The device can predict the changes that the product will encounter outdoors very well.

The simulation of ultraviolet (UV) and sunlight, although UV only accounts for 5% of sunlight, is the main lighting factor causing a decrease in the durability of outdoor products. This is because the photochemical reaction of sunlight increases with the decrease of wavelength. Therefore, when simulating the destructive effect of sunlight on the physical properties of materials, it is not necessary to reproduce the entire sunlight spectrum. In most cases, only short wave UV light needs to be simulated.

The reason why UV lamps are used in UV aging chambers is that they are more stable than other lamps and can better reproduce test results. The best method is to use fluorescent UV lamps to simulate the impact of sunlight on physical properties, such as brightness reduction, cracking, peeling, etc.

There are several different types of UV lights to choose from. Most of these UV lamps mainly produce ultraviolet light, rather than visible and infrared light. The main difference between lamps is reflected in the total UV energy generated within their respective wavelength ranges. Different lights will produce different test results. The actual exposure application environment can prompt which type of UV lamp should be used.

Application of UV aging chamber:
1. Simulate sunlight：
The ultraviolet rays in sunlight are the main factor causing damage to the durability of most materials. We use ultraviolet lamps to simulate the shortwave ultraviolet part of sunlight, which generates very little visible or infrared spectral energy.
We can choose UV lamps with different wavelengths based on different testing requirements, as each lamp has different total UV irradiation energy and wavelength. Usually, UV lamps can be divided into two types: UVA and UVB.

2. Wet condensation environment：
In many outdoor environments, materials can be damp for up to 12 hours per day. Research has shown that the main factor causing outdoor humidity is dew, not rain. The UV aging test chamber simulates outdoor moisture erosion through its unique condensation function.

During the condensation cycle during the experiment, the water in the bottom reservoir of the test chamber is heated to generate hot steam, which fills the entire test chamber. The hot steam maintains the relative humidity of the test chamber at 100% and maintains a relative high temperature. The sample is fixed on the side wall of the testing room, so that the test surface of the sample is exposed to the ambient air in the testing room.
The exposure of the outer side of the sample to the natural environment has a cooling effect, resulting in a temperature difference between the inner and outer surfaces of the sample. The appearance of this temperature difference results in liquid water generated by condensation on the test surface of the sample throughout the entire condensation cycle.

Due to outdoor exposure to moisture for up to ten hours per day, a typical condensation cycle typically lasts for several hours. The UV aging test chamber provides two moisture simulation methods.
The most commonly used method is condensation, which simulates outdoor moisture erosion. All UV aging test chambers can operate condensation cycles. Because some application conditions also require the use of water spray to achieve practical results, some UV aging test chambers can operate both condensation and water spray cycles.

3. Temperature control
In each cycle, the temperature can be controlled at a set value. At the same time, the blackboard thermometer can monitor the temperature. An increase in temperature can accelerate the aging process, and temperature control is also important for the reproducibility of testing.

Water spray system；
For some applications, water spraying can better simulate the environmental conditions of final use. Water spray is very effective in simulating Thermal shock or mechanical erosion caused by temperature upheaval and rain wash.
In some practical application conditions, such as sunlight, when the accumulated heat dissipates rapidly due to sudden showers, the temperature of materials will change sharply, resulting in Thermal shock. This Thermal shock is a test for many materials. The water spray of the ultraviolet aging test chamber can simulate Thermal shock and/or stress corrosion.

UV aging test method:
Irradiance: 0.89W/m; Wavelength: 340nm; Exposure cycle: (60 ± 3 ℃) UV irradiation at black panel temperature for 8 hours; Condensing for 4 hours at a black panel temperature of (50 ± 3 ℃); Duration: 100 hours; Part of the sample is covered with Aluminium foil, and the other part is exposed. After the test, conduct a grey scale comparison between the wrapped and exposed parts to evaluate the grey scale level.

When operating the UV aging chamber, the following points should be noted:
1. The placement and layout of samples should be reasonable to avoid mutual obstruction and affect the test results.
2. The placement of samples should be careful not to come into contact with the metal components inside the test chamber to avoid interference that may affect the test results.
3. During the testing process, it is necessary to regularly clean the UV lamp tubes and reflective plates inside the test chamber to ensure testing accuracy.
4. Before testing, it is necessary to calibrate the irradiation intensity and wavelength of the ultraviolet lamp tube to ensure the accuracy of the test results.

UV aging test Chamber is designed for evaluating the resistant performance of non-metallic materials, organic materials (plastics, paints, coatings, rubbers, etc.) under the specified conditions such as sunlight, temperature, and other climatic conditions. It creates a man-made testing environment imitating the natural light source such as sunlight and other damages in the nature, such as rain and dew damage, to impose on the materials and to assess the degree of color changing and fading under the accelerated environment conditions. The chamber fully complies with the requirements of Standard ISO 4892-1, ISO 4892-3, GB/T16585-1996, GB14522-93, GB/T16422.3-1997, ASTMG53 and etc., provides the best UV sunlight simulation, and is easy to use and operate.

Lisun Instruments Limited was found by LISUN GROUP in 2003. LISUN quality system has been strictly certified by ISO9001:2015. As a CIE Membership, LISUN products are designed based on CIE, IEC and other international or national standards. All products passed CE certificate and authenticated by the third party lab.

Our main products are Goniophotometer, Integrating Sphere, Spectroradiometer, Surge Generator, ESD Simulator Guns, EMI Receiver, EMC Test Equipment, Electrical Safety Tester, Environmental Chamber, Temperature Chamber, Climate Chamber, Thermal Chamber, Salt Spray Test, Dust Test Chamber, Waterproof Test, RoHS Test (EDXRF), Glow Wire Test and Needle Flame Test.

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