Methods Of Exposure To Laboratory Light Sources – Part 3: Fluorescent UV Lamps
ISO 4892-3 details various methods that characterize the effects of weathering of plastic components through the use of UV testing. This Standard is equivalent to ASTM G154 and relies on the use of fluorescent UV lamps. Micom offers ISO 4892-3 testing as part of its coating testing services.
UV fluorescent lamps exposure – method use and factors to consider
ISO 4892-3 is a standard that specifies the test conditions duplicating weathering effects on plastic components. This test is done with UV fluorescent lights whereas ISO 4892-2 relies on the use of xenon arc lamps as an illuminating source. Furthermore, the fluorescent lights that are discussed in ISO 4892-3 are: UVA-340, UVA-351, UVB-313 or a combination of four fluorescent lamps. The lamp that is the most recommended in weathering is UVA-340. Indeed, it is because its spectral distribution is very similar to the sun and this is especially true at low wavelengths. On the other hand, the one that is prescribed to simulate accelerated aging behind a glass window is UVA-351, because its spectral distribution is a good approximate of this phenomenon. Lastly, as mentioned in our UV testing eBook, accelerated fluorescent UV exposure is essentially used to assess the loss of mechanical properties of the material.
The main factors that are in play when conducting an exposure are: the type of UV lamp, the irradiance level, the temperature during wetting and during the UV exposure and the timing of each part of the cycle.
Typical Experimental parameters
The number samples required is three and it is recommended to test them concurrently with a material of known performance, so that the latter one can be used as a control. Table 1 lists the mainly used parameters for the test.
Table I: Typical experiment parameters for the ISO-4892-3 method
Other test methods related to ISO 4892-3
For additional related test methods, please see ISO 4892 and ISO 4582.
Practical UV Testing Guide
Sunlight exposure can have harmful impacts on carbon-based
materials such as coatings, polymers, textiles, and many others.
Learn more about our in-laboratory UV testing process in this guide.