ASTM D3361/D3361M-22

SIGNIFICANCE AND USE 4.1 The ability of a paint or coating to resist deterioration of its physical and optical properties caused by exposure to light, heat, and water can be very significant for many applications. This practice is intended to induce property changes associated with end-use conditions, including the effects of sunlight, moisture, and heat. The exposure used in this practice is not intended to simulate the deterioration caused by localized weather phenomena such as atmospheric pollution, biological attack, and saltwater exposure. 4.2 Cautions—Variation in results may be expected when different operating conditions are used. Therefore, no reference to the use of this practice shall be made unless accompanied by a report prepared according to Section 10 that describes the specific operating conditions used. Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained according to this practice. Note 1: Additional information on sources of variability and on strategies for addressing variability in the design, execution, and data analysis of laboratory accelerated exposure tests is found in Guide G141. 4.2.1 The spectral power distribution of light from an unfiltered open-flame carbon arc is significantly different from that produced in light and water exposure devices using other carbon-arc configurations or other light sources. The type and rate of degradation and the performance rankings produced by exposures to unfiltered open-flame carbon-arcs can be much different from that produced by exposures to other types of laboratory light sources. Typically, exposures conducted according to this practice will produce degradation faster than similar exposures conducted in accordance with Practice D822/D822M or D5031/D5031M and may cause different types of degradation. 4.2.2 Interlaboratory comparisons are valid only when all laboratories use the same type of carbon-arc and exposure conditions. 4.3 Reproducibility of test resu... SCOPE 1.1 This practice covers the selection of test conditions for accelerated exposure testing of coatings and related products in unfiltered open-flame carbon-arc devices conducted according to Practice G151 and G152. This practice also covers the preparation of test specimens, the test conditions suited for coatings, and the evaluation of test results. 1.2 This practice covers unfiltered open-flame carbon-arc exposures of paints and related coatings, and covers the exposure cycle that has been commonly referred to as the “dew cycle.” Practice D822/D822M describes filtered open-flame carbon-arc devices, and Practice D5031/D5031M describes enclosed carbon-arc exposures. The radiation from an unfiltered open-flame carbon arc produces shorter wavelengths and higher levels of short wavelength radiation than either filtered open-flame or enclosed carbon arcs. 1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.