AATCC 111-2015 Weather Resistance of Textiles: Exposure to Daylight and Weather.
2. Principle
2.1 Test specimens and the agreed upon comparison standard(s) are exposed simultaneously to natural weathering, either Directly or Behind Window Glass, either to a specified degree of degrada- tion such as color change, strength loss, etc., or alternately to a specific amount of radiant energy. Exposures can be timed by calendar days, months, or years as well. However, this method can result in more variation when comparing test exposures for equal duration at different time periods. The weather resistance of the material is determined by the exposed portion of the test specimens to an unex- posed counterpart, using one or more of the procedures recommended in this test method.
3. Terminology
3.1 AATCC Blue Wool Lightfastness Standard, n.—one of a group of dyed wool fabrics distributed by AATCC for use in determining the amount of light exposure of specimens during lightfast- ness testing.
3.2 Black Panel Thermometer, n.—a temperature measuring device, the sens- ing unit of which is coated with black de- signed to absorb most of the radiant en- ergy encountered in lightfastness testing.
3.3 breaking strength, n.—the maxi- mum force applied to a specimen in a ten- sile test carried to rupture.
3.4 broad bandpass radiometer, n.— a relative term applied to radiometers that have a bandpass width of more than 20 nm at 50% of maximum transmittance and can be used to measure irradiance at wavelengths such as 300-400 nm or 300 – 800 nm.
3.5 bursting strength, n.—the force or pressure required to rupture a textile by distending it with a force applied at right angles to the plane of the fabric, under specified conditions.
3.6 center wavelength, n.—the speci- fied wavelength midway between the half power points, for example, 340 nm ± 2 nm.
3.7 color change, n.—a change in color of any kind whether in lightness, hue or chroma or any combination of these, discernible by comparing the test specimen with a corresponding untested specimen. Source: Evaluation Procedures 1 and 7.
3.8 half-power bandpass, n.—the interval between wavelengths at which transmittance is 50% of peak transmit- tance in a bandpass filter. NOTE: The interval should not exceed 20 nm for a nar- row bandpass filter.AATCC 111 pdf download.