Weathering Tests for the Highest Demands

UV light in sunlight and diffuse sky radiation is especially important. It can cause alterations in the surface of materials, which – accelerated by other climate factors, such as temperature and humidity – lead to the typical symptoms of ageing. Staggered simulations of natural weathering in devices always requires a restriction of the number of climate values or their cyclic alterations. The Global-UV test unit simulates the most important climate factors which are relevant for ageing.

Features

• Weathering tests according to DIN EN ISO 4892-3 procedure A (lamp combination) cycle number 3+ 4, DIN EN 12224, VDI 3958 page 12, DIN EN 1297 and EOTA TR-010 with high temperature and humidity constancy and aerosol-free humidification.
• Universal use in the framework of tests, materials development and damage assessments: Simulation of extreme climates and of acid rain (pH value ≥ 3), e. g. for the ADF (acid dew and fog) and the AR (acid rain) test (VDI 3958 page 12).
• Weathering of specimens and components with large surface areas
• Efficient ratio of useful test space area and installation surface
• Removable radiation door which is easily opened for good access to the test chamber
• The spectral irradiance can be varied by means of the use of other fluorescent lamps
• Folding screen made of special safety glass for easy access to light sources
• Environmentally friendly materials
• Low investment, operating and maintenance costs

Application

In other test procedures, too much attention is paid to the simulation of the entire global radiation and the simulation of other important climate factors is neglected. However, it is also important that temperature conditioning and humidification are controlled in a reproducible manner and that the air is humidified without aerosols. Moreover, any uncontrolled overheating on account of the radiant heat of the lamps has to be prevented. Test procedures according to DIN EN ISO 4892-2 prescribe e. g. the simulation of the overall range of global radiation, the disadvantage of which is that the influencing factors of specimen temperature and humidity or their cyclic alterations can only be controlled very vaguely. In test procedures with fluorescent lamps according to DIN EN ISO 4892-3 only the simulation of the photochemically effective spectral range ≤400 nm (UV-A and UV-B radiation) is prescribed. This means we dispense with radiation heating of the specimens but gain the possibility of climate conditioning the specimens in the entire natural temperature and humidity range in a precise and reproducible manner. Within the UV-Global test unit, radiation is effected with special fluorescent lamps in the wavelength range from 290 nm to 450 nm.