Xenon arc tester irradiance control

Artificial accelerated aging testers can be divided into different types according to the light source, such as: B. Carbon arc lamps, fluorescent UV lamps, xenon lamps, etc. Xenon lamps have become the world\'s most widely used light source for artificial accelerated aging. Its spectral distribution is closest to sunlight after being filtered by filter glasses. It can simulate the sunlight inside and outside the house, its radiation intensity can be controlled, and its service life is long. The working mode of the xenon lamp determines that its irradiance is stable and controllable, and no exhaust gas is generated during the working process. The relative spectral power distribution of the Xenon-Lamon lamp changes with the user over its lifetime. Xenon lamps are the preferred light source for artificial accelerated aging tests due to their significant advantages.

The control of the BXenon arc lamp irradiance is critical to ensure accurate and reliable xenon arc tester test results. In general, there are three factors that affect the irradiance on the samples in the xenon arc chamber: the filtering action of the filter glass, the homogeneity of the sample receiving light irradiance, and the irradiance monitoring and feedback system.

The filter effect

In color fastness to light test conditions, the UV filter glass is placed between the light source and the sample so that the ultraviolet spectrum is steadily attenuated. The transmittance of the filter glass used should be at least 90% in between. The infrared radiation energy in the spectrum of the xenon lamp can be stably reduced, indby placing the filtered optical infrared glass between the light source and the samples. The eEffective isolation of ultraviolet and infrared light can stably control the light irradiance.

After filtering through the infrared spectrum filter glass and UV filter glass, the irradiance of the infrared spectrum of the xenon lamp is reduced, and the ultraviolet light also becomes effective filtered out (in nature, the ultraviolet light is absorbed by ozone as sunlight penetrates the atmosphere) so that the spectrum of the xenon lamp that reaches the sample surface closely matches the natural spectrum of sunlight. Therefore the main purpose of the filter glass is to obtain the desired spectral energy distribution. The selection and quality of the filter glasses has a major impact on the final irradiation intensity. By combining different glass properties of cylindrical filters in Xenonlampen illumination systems, different spectral ranges can be achieved. Energy distributions can be generated.

Irradiation homogeneity on the samples causes

The distance between the lamp and the sample also affects the irradiance and the uniformity of the irradiance, which affects the samples.

Light irradiance uniformity can be effectively solved by rotating the sample rack in the drum xenon arc tester. The sample The holder and the xenon lamp are installed on a concentric shaft, and each exposed sample has the same distance from the xenon lamp, and the spectrum reflected from the chamber has the same influence on each sample. In the vertical direction, the length of the xenon lamp luminescence zone is greater than the exposure length of the sample clamp, and the resulting inhomogeneity of light irradiation generally does NOT exceed the allowable E device, whathas limited impact on test results. TheReface, the university for light exposure in The test box is well guaranteed.

Radiation monitoring and feedback system

After a period of use, the xenon lamp and filter continuously decrease their luminous efficacy and increase the heating capacity while consuming the same power source. At the same time, the filter also ages, so the irradiance and temperature of the test chamber may not reach the set value. Therefore, to monitor, we need the irradiance monitoring and feedback system and adjust the irradiance to ensure that the xenon arc lamp provides an even irradiance.

How does the monitoring and feedback system work? After the xenon lamp spectrum is corrected by the filter, the selected wide (or narrow) irradiance is displayedstrength sensor monitored. After comparing with the preset wide (or narrow) irradiance value, the xenon lamp power supply current is automatically adjusted (within the allowable range of the xenon lamp) to increase or decrease it, constant irradiance can be achieved. The constant irradiance of the xenon lamp is compensated by the excess power of the xenon lamp, so the maximum power of the xenon lamp indicated by the instrument indicates the upper limit of its usable PoWer and does not mean that the xenon lamp in the instrument is always used at this power. High power xenon lamps have a larger compensation range and are likely to last longer. How to keep the monitoring and feedback system accurate? Periodic calibration procedures such as periodic replacement of lamps and filters and periodic calibration of the radiation sensor canensure the accuracy and reliability of the system.