摘要 |
The usual xenon radiation source in conventional weathering testers is replaced by UV light-emitting diodes (LEDs) ( 6 ). These can be used to provide a good approximation of the UV component of the solar spectrum, in particular when different types of UV light-emitting diodes ( 6 ) with different emission characteristics are employed. Optionally, further light-emitting diodes in the visible spectral range may also be used in order to cover other parts of the solar spectrum. The light-emitting diodes ( 6 ) may be mounted on a flexible printed circuit board ( 5 ), which may in turn be fitted on a tubular holding body ( 4 ). The flexible printed circuit board carrying the light-emitting diodes may also be placed on other substrates ( 7 ) which are pliable in a geometrically stable way, so that that they can be arranged at a uniform distance from material samples with a particular surface topology, in order to obtain uniform exposure.
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