LIGHT FASTNESS AND WEATHERING TESTER

PURPOSE: To appropriately irradiate a test piece with radiation by providing a tubular radiation source and an infrared-ray absorbing surface passing through the axis of the source in a tubular filter which transmits ultraviolet rays and visible light, but reflects infrared rays. CONSTITUTION: A tubular cylindrical filter 1 surrounds a tubular radiation source 2 with the axis 4 of the filter 3 in parallel with that 3 of the source 2 and an infrared ray absorbing surface 5 is provided through the axes 3 and 4. A filter layer 6 which transmits ultraviolet rays and visible light, but reflects infrared rays, is formed on the internal surface of the filter l and infrared rays radiated from the source 2 are discharged as heat, because the rays are reflected by the layer 6 and absorbed by the surface 5. Since the source 2 is exccentrically arranged from the axis 4 of the filter 4, all infrared rays reflected by the internal surface of the filter 1 reach the surface 5. Therefore, a test piece can be irradiated with radiation by absorbing most of the infrared rays without reducing the infrared rays and visible light radiated to the outside.