ASTM G151-2019 pdf free download

ASTM G151-2019 pdf free download.Standard Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
1. Scope
1.1 This practice covers general procedures to be used when exposing nonmetallic materials in accelerated test devices that use laboratory light sources. Detailed information regarding procedures to be used for specific devices are found in standards describing the particular device being used. For example, detailed information covering exposures in devices that use open flame carbon arc, enclosed carbon arc, xenon arc, and fluorescent UV light source are found in Practices G152, G153, G154, and G155 respectively. N OTE 1—Carbon-arc, xenon arc, and fluorescent UV exposures were also described in Practices G23, G26, and G53 which referred to very specific equipment designs. Practices G152, G153, and G154, and G155 are performance based standards that replace Practices G23, G26, and G53. 1.2 This practice also describes general performance re- quirements for devices used for exposing nonmetallic materials to laboratory light sources. This information is intended primarily for producers of laboratory accelerated exposure devices. 1.3 This practice provides information on the use and interpretation of data from accelerated exposure tests. Specific information about methods for determining the property of a nonmetallic material before and after exposure are found in standards describing the method used to measure each prop- erty. Information regarding the reporting of results from exposure testing of plastic materials is described in Practice D5870. N OTE 2—Guide G141 provides information for addressing variability in exposure testing of nonmetallic materials. Guide G169 provides informa- tion for application of statistics to exposure test results. N OTE 3—This standard is technically equivalent to ISO 4892, Part 1. 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 appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Significance and Use
4.1 Significance: 4.1.1 When conducting exposures in devices that use labo- ratory light sources, it is important to consider how well the accelerated test conditions will reproduce property changes and failure modes associated with end-use environments for the materials being tested. In addition, it is essential to consider the effects of variability in both the accelerated test and outdoor exposures when setting up exposure experiments and when interpreting the results from accelerated exposure tests. 4.1.2 No laboratory exposure test can be specified as a total simulation of actual use conditions in outdoor environments. Results obtained from these laboratory accelerated exposures can be considered as representative of actual use exposures only when the degree of rank correlation has been established for the specific materials being tested and when the type of degradation is the same. The relative durability of materials in actual use conditions can be very different in different locations because of differences in UV radiation, time of wetness, relative humidity, temperature, pollutants, and other factors. Therefore, even if results from a specific exposure test con- ducted according to this practice are found to be useful for comparing the relative durability of materials exposed in a particular exterior environment, it cannot be assumed that they will be useful for determining relative durability of the same materials for a different environment.