3 light sources commonly used by Accelerated Weathering Tester

At present, the artificial light sources used by the Accelerated Weathering Tester all try to make the energy spectrum distribution curve in this wavelength range close to the solar spectrum. Simulation and acceleration magnification are the main basis for selecting artificial light sources. After about a century of development, laboratory light sources have various light sources such as enclosed carbon arc lamps, sunlight-type carbon arc lamps, fluorescent ultraviolet lamps, xenon arc lamps, and high-pressure mercury lamps. The technical committees related to polymer materials in the International Organization for Standardization (ISO) mainly recommend the use of three light sources: sunlight-type carbon arc lamps, fluorescent ultraviolet lamps, and xenon arc lamps.

1. Xenon arc lamp

At present, it is believed that the spectral energy distribution of xenon arc lamps in known artificial light sources is most similar to the ultraviolet and visible parts of sunlight. By choosing an appropriate filter, most of the shortwave radiation present in sunlight reaching the ground can be filtered out. The xenon lamp has strong radiation in the infrared region of 1000nm~1200nm, which will generate a lot of heat.

Therefore, a suitable cooling device must be selected to take away this part of the energy. At present, there are two cooling methods for xenon lamp aging test devices on the market: water-cooled and air-cooled. Generally speaking, the cooling effect of the water-cooled xenon lamp device is better than that of the air-cooled device, and the structure is also more complicated and the price is more expensive. Since the energy of the ultraviolet part of the xenon lamp increases less than the other two light sources, it is the lowest in terms of acceleration magnification.

Applicable situation: plastic industry, rubber industry, paint industry, dyes, pigments, textiles, etc.

Commonly used standards: GB/T 16422.2, ISO 4892-2, SAE J2527, ASTM G 155, ASTM D4459, etc.

2. Fluorescent UV lamps

Theoretically, the short-wave energy of 300nm~400nm is the main factor causing aging. If you increase this part of the energy, you can achieve the effect of rapid testing. The spectral distribution of fluorescent UV lamps is mainly concentrated in the ultraviolet part, so a higher acceleration rate can be achieved.

However, fluorescent UV lamps not only increase the UV energy in natural sunlight, but also radiate energy that is not present in natural sunlight when measured at the Earth's surface, and this part of the energy can cause unnatural damage. In addition, the fluorescent light source has no energy higher than 375nm except for the very narrow mercury spectral line, so that materials sensitive to longer wavelength UV energy may not experience the same changes as exposure to natural sunlight. Unreliable results can result from these inherent flaws.

Therefore, the simulation of fluorescent UV lamps is poor. However, due to its high acceleration rate, rapid screening of specific materials can be achieved by selecting the appropriate type of lamp.

Application: widely used in non-metallic materials, organic materials (such as: coatings, paints, rubber, plastics and their products)

Commonly used standards: GB/T 16422.3, ISO 4892-3, ASTM G154, SAEJ 2020, IEC 61215, etc.

3. Sunlight type carbon arc lamp

Sunlight type carbon arc lamps are rarely used in my country, but they are widely used light sources in Japan, and most JIS standards use sunlight type carbon arc lamps. Many Chinese auto companies that are joint ventures with Japan still recommend the use of this light source. The spectral energy distribution of the sunlight-type carbon arc lamp is also closer to that of sunlight, but the ultraviolet rays are concentrated at 370nm~390nm, and the simulation is not as good as that of the xenon lamp, and the acceleration rate is between the xenon lamp and the ultraviolet lamp.

Applicable situation: Generally, the sunlight type weatherproof machine is more suitable for coating industry, automobile industry, construction industry, communication equipment, textile industry, dye chemistry, rubber industry, etc. Now it is mainly used for the testing of automobile materials, especially in Japanese enterprises.

Commonly used standards: GB/T 16422.4, GB/T 15255, ISO 4892-4, ASTM G152, JIS D0205, etc.

For more information about UV Accelerated Weathering Tester, please pay attention to QINSUN instrument!

2022-02-16 15:38