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.
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.
摘要:
The invention concerns the ageing of material samples in the test enclosuref an apparatus for testing exposure to light and weathering, using visible light, UV light and medium- or long-wavelength IR radiation and with air circulation. In order to ensure reproducible test results, a value representing the surface temperature of the sample is measured by means of a temperature sensor and compared, at the input of a control unit, with a predefined reference temperature. In the event of a temperature difference, a control signal generated by the control unit adjusts the power supply to a separate IR radiant heater for medium- and long-wavelength IR radiation in such a way that the difference disappears in accordance with a predefined indicial response.