Rosehill TPV® granules are tested in a QUV Weatherometer Machine, manufactured by Q-LAB.
The granules are exposed to alternating cycles of UV light and condensation.
They are measured on a standard Grey Scale after 1000 hours exposure.
Readings are recorded between 1 and 5.5 (5.5 representing no change and 1, significant change).
A minimum resistance of 3 is required by DIN standards.