Which is a good fluorescent UV lamp aging test chamber

The damage of natural sunlight and moisture to materials causes incalculable economic losses every year. The UV accelerated weathering tester can reproduce the damage caused by sunlight, rain, and dew. The device conducts experiments by exposing the tested material to controlled cycles of sunlight and moisture, while increasing the temperature. The equipment uses ultraviolet fluorescent lamps to simulate sunlight, and can also simulate moisture effects through condensation or spraying.

In just a few days or weeks, the device can reproduce the damage that would take months or years outdoors. The damage caused mainly includes fading, discoloration, decreased brightness, powdering, cracking, blurring, brittleness, decreased strength, and oxidation. The test data provided by the equipment is of great help in selecting new materials, improving existing materials, or evaluating compositional changes that affect product durability. The device can predict the changes that the product will encounter outdoors.

Simulation of Ultraviolet (UV) and Sunlight

Intelligent UV aging test chamber(UV) only accounts for 5% of sunlight, but it is the main lighting factor causing a decrease in the durability of outdoor products. This is because the photochemical reaction of sunlight increases as the wavelength decreases. Therefore, when simulating the destructive effects of sunlight on the physical properties of materials, it is not necessary to reproduce the entire spectrum of sunlight. In most cases, simulating short wave UV light is sufficient. The reason why UV accelerated weathering testing machines use UV lamps is that they are more stable than other lamps and can better reproduce test results. Using fluorescent UV lamps to simulate the effects of sunlight on physical properties, such as decreased brightness, cracking, peeling, etc., is a method. There are several different types of UV lamps to choose from. Most of these UV lamps mainly produce ultraviolet light, rather than visible and infrared light. The main difference between lamps lies in the total UV energy they generate within their respective wavelength ranges. Different lights will produce different test results. The actual exposure application environment can indicate which type of UV lamp should be selected.

The advantages of fluorescent lamps are: fast acquisition of test results; Simplified illumination control; Stable spectrum; Requiring minimal maintenance; The price is cheap and the operating costs are reasonable.

UVA-340， Simulating the ultraviolet spectrum of sunlight, it can simulate the critical short wave wavelength range of sunlight spectrum, which is the spectrum in the wavelength range of 295-360nm. UVA-340 only produces the spectrum of UV wavelengths that can be found in sunlight.

UVB-313， The acceleration test used can quickly provide test results. The short wavelength UV they use is stronger than the UV light waves commonly found on Earth today. Although these UV lights, which are much shorter than natural wavelengths, can accelerate experiments, they can also cause non compliant and actual degradation damage to certain materials.

A fluorescent ultraviolet lamp that emits light energy below 300nm, which is less than 2% of the total output light energy, is commonly referred to as UV-A lamp; A fluorescent ultraviolet lamp that emits light energy below 300nm, which is greater than 10% of the total output light energy, is commonly referred to as a UV-B lamp;

The UV-A wavelength range is 315-400nm, while the UV-B wavelength range is 280-315nm;

Simulate the effects of rainwater and dew

Intelligent UV aging test chamberThe time that outdoor materials come into contact with moisture can last up to 12 hours a day, and research results show that the main cause of this outdoor moisture is dew, not rainwater. The UV accelerated weathering tester simulates the effects of outdoor moisture through a series of condensation principles. In the condensation cycle of the equipment, there is a water storage tank at the bottom of the box, which is heated to generate water vapor. Hot steam maintains the relative humidity inside the test chamber in a saturated state 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 indoor ambient air. The cooling effect of indoor air causes the surface temperature of the specimen to drop to a level several degrees below the steam temperature. The occurrence of this temperature difference results in the presence of liquid water generated by condensation on the surface of the specimen throughout the entire condensation cycle. This condensation product is very stable pure distilled water. This purified water improves the reproducibility of the experiment while avoiding water stains.

Due to the fact that outdoor exposure to moisture can last up to 12 hours per day, the humidity cycle of UV accelerated weathering testing machines generally lasts for several hours. We recommend that each condensation cycle last at least 4 hours. Note that UV exposure and condensation exposure in the equipment are carried out separately, which is consistent with the actual climate conditions.

For certain application processes, water spray can better simulate the environmental conditions of final use. Water spraying is extremely useful in simulating mechanical erosion caused by temperature fluctuations and rainwater erosion. Roofs, automotive materials, and coatings used on metal buildings or structures often experience sudden temperature fluctuations. For example, in hot summer, when the heat accumulates, it suddenly dissipates due to rainstorm. The consequences of such temperature fluctuations are a challenge for many materials. The UV accelerated weathering tester/spray type is specifically designed to reproduce this condition.

Due to frequent erosion from rainwater, the coating layer of wood, including paint and coloring agents, will experience corresponding erosion phenomena. Recent research has shown that this rainwater washing action can wash away the anti degradation coating layer on the surface of the material, thereby directly exposing the material itself to the destructive effects of UV and moisture. This process can be repeated multiple times, resulting in a material degradation phenomenon that cannot be reproduced solely by condensation.

Reference standards

This UV accelerated weathering testing machine is suitable for performance reliability testing of various industrial products. It is designed and manufactured in accordance with the corresponding standard clauses such as GB/T14522-93 "National Standard of the People's Republic of China - Plastic, Coating, Rubber Materials for Mechanical Industry Products - Accelerated Test Method for Artificial Climate" GB/T16585-1996 (GB/T3511-2008) "National Standard of the People's Republic of China - Test Method for Artificial Climate Aging of Vulcanized Rubber (Fluorescent UV Lamp)" and GB/T16422.3-1997 "Laboratory Light Source Exposure Test Method for Plastics";

Compliant with international testing standards: ASTM D4329, D499, D4587, D5208, G154, G53; ISO 4892-3、ISO 11507； EN 534； prEN 1062-4、 BS 2782； JIS D0205； SAE J2020 and other UV aging test standards.

Using a light source

The light source uses 8 imported ultraviolet fluorescent lamps with a rated power of 40W as the light source. Ultraviolet fluorescent tubes are distributed on both sides of the machine, with 4 on each side. There are UVA-340 and UVB-313 light sources available for users to choose from and configure;

The UV-A wavelength range is 315-400nm, and the luminescence spectrum energy of the lamp is mainly concentrated at the wavelength of 340 nm;

The UV-B wavelength range is 280-315nm, and the luminescence spectrum energy of the lamp is mainly concentrated at the wavelength of 313nm;

Due to the gradual decay of UV light energy output over time, in order to reduce the experimental impact caused by light energy decay, this test chamber replaces an old lamp with a new lamp every 1/4 of the fluorescent lamp life (lamp life: 1600H) among the eight lamps. The position of the new lamp is changed as shown in the figure below, so that the UV light source is always composed of new and old lamps, thus obtaining a constant output of light energy;

2、 Main technical specifications and parameters of the equipment

1. Studio size: 350 × 1150 × 410mm;

2. Dimensions: 580 × 1280 × 1450mm;

3. Temperature range: RT+10 ℃~90 ℃;

4. Humidity range: 90-98% R? H;

5. Humidity uniformity: ± 2%;

6. Temperature uniformity: ± 2 ℃;

7. Temperature fluctuation: ± 0.5 ℃;

8. Humidity fluctuation: ± 2%;

9. Temperature control method: PID self-tuning temperature control method;

10. Center distance of the lamp: 70mm;

11. Distance between sample and lamp center: 50mm;

12. Import American light tubes;

13. Standard specimen size: 75 × 150mm or 75 × 300mm (special specifications need to be specified in the contract);

14. Water depth requirement for the sink: 25mm, automatic control;

15. Effective irradiation area: 900 × 210mm;

16. Ultraviolet wavelength: UV-A wavelength range is 315-400nm; UV-B wavelength range is 280-315nm;

17. Test time: 0-9999H, M, S adjustable;

18. Blackboard temperature: adjustable from 40 ℃ to 75 ℃;

19. UV light and condensation time can be adjusted;

20. The spraying time can be adjusted;

3、 Test box structure

1. Inner liner material: SUS304 stainless steel plate;

2. Box cover material: SUS304 stainless steel plate spray treated;

3. Install a total of 8 UV-A or UV-B ultraviolet lamps on both sides of the studio;

4. The heating method is the inner pot sink type heating, which heats up quickly and has a uniform temperature distribution;

5. The lid is a double-sided flip cover, which can be easily opened and closed;

6. The inner tank water level automatically replenishes to prevent the heating tube from burning out and being damaged;

7. The sample holder is made of stainless steel or aluminum alloy;

8. The bottom of the test chamber adopts high-quality fixed PU movable wheels;

9. The drainage system uses vortex and U-shaped sedimentation devices for drainage;

10. The surface of the sample is parallel to the plane of the ultraviolet lamp;

11. The spray type equipment is equipped with automatic nozzles inside, and the water pressure can be adjusted;

12. If the lamp is on and the door of the box is opened, the machine will automatically cut off the power supply to the lamp and enter a balanced state for cooling to prevent harm to the human body;

13. Over temperature protection inside the box. When the temperature inside the box is too high, the machine will automatically cut off the power and enter a balanced state for cooling.

14. Box shell material: SUS304 stainless steel plate spray treated;

4、 Control and protection system

1. Intelligent Korean "ternary" temperature controller with a control accuracy of ± 0.1 ℃;

2. Thin film KEY BOARD button;

3. Temperature control adopts P.I.D+S.S.R, and the system coordinates control with the same channel, which can improve the stability and service life of control components and interfaces;

4. Touch sensitive settings, digital and direct display;

5. It has the function of automatic calculation of P. I. D, which can reduce the inconvenience caused by manual setting;

6. Lighting and condensation can be independently controlled or alternately controlled in a cyclic manner;

7. The independent control time and alternating cycle control time for lighting and condensation can be set arbitrarily within one thousand hours;

8. In operation or setting, if an error occurs, a warning signal will be provided;

9. Schneider Electric components from France;

Temperature control

UV cycle

The first-order photochemical reaction is not sensitive to temperature changes. However, the speed of the subsequent secondary reaction is closely related to temperature changes. Generally speaking, as the temperature increases, the reaction rate will accelerate. Therefore, in the process of UV exposure testing, temperature control becomes very important, and more importantly, it is necessary to match the test temperature used in the accelerated test with the high temperature encountered by the material in practical applicationsThe temperature matches. The temperature setting of UV in the device can be any point from 50 ℃ to 90 ℃, depending on the level of illumination and indoor ambient temperature. The temperature regulation of the equipment is controlled by a controller with microcomputer calculation function to command a series of systems inside the equipment, such as air heaters, water heaters, etc.

Moisture cycle

As the temperature increases, the destructive power of moisture on materials will sharply increase. Therefore, temperature control is the most basic requirement during wet exposure. Furthermore, to achieve an acceleration effect, it is necessary to maintain a high temperature environment during the wet exposure process. The temperature setting for the condensation process in the device can be any point from 40 ℃ to 80 ℃.

Heating system

Adopting U-shaped titanium alloy high-speed heating electric heating tube;

Temperature control and lighting independent system;

The temperature control output power is calculated by a microcomputer to achieve high-precision and high-efficiency electricity efficiency;

L has an anti overheating function with a heating system;

The temperature of the black aluminum plate is controlled by an intelligent "ternary" series Korean temperature controller, and the output power is calculated by a microcomputer with PID self-tuning. The monitoring adopts standard Pt-100 blackboard temperature sensor;

The temperature of the sink is also controlled by a Korean "three element" temperature controller for heating. The sink is located at the bottom of the box and is equipped with an electric water heater. During the cyclic testing process, there is a testing section called the dark condensation process, which requires the box to generate saturated water vapor at a relatively high temperature. When the water vapor encounters a relatively cold surface of the sample, it will condense on the surface of the sample.

5、 Protection system

1. Non fuse protection switch;

2. Overtemperature;

3. Low water level; Overload;

4. Leakage; Door opening protection;

5. Fully sheathed terminal block;

6. Protection such as automatic shutdown;