Jun 21, ASTM G – Designation: G – 09 Standard Practice for Exposing Nonmetallic Materials in Ac. ASTM G UV EXPOSURE (GENERAL). This practice provides general procedures to be used when exposing nonmetallic materials in accelerated test. Buy ASTM G Standard Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources from SAI Global.
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Even though it is very tempting, calculation of an acceleration factor relating x h or megajoules of radiant exposure in a laboratory accelerated test to y months or years of exterior exposure is not recommended. An astm g151 of a statistical analysis using multiple laboratory and exterior astm g151 to calculate an acceleration factor is described by G15.
Specific information about methods for determining the property of a nonmetallic material before astm g151 after exposure are found in standards satm the method used to measure each property. Note 5-Definitions for control and reference material that are appropriate to weathering tests astm g151 found in Terminology G The relative durability of materials in actual use conditions can be very different g1551 different locations because of differences in UV radiation, time astm g151 wetness, relative humidity, temperature, pollutants, and other factors.
Exposure conditions that produce unrealistic temperature differences between light and dark colored specimens.
ASTM G – UV EXPOSURE (GENERAL)
In some cases, a reference material is exposed at the same time as a test material and the exposure is conducted astm g151 there is a defined change in property of the reference material.
Absence of biological agents or pollutants. Test astm g151 where specimens are exposed continuously to light when actual use conditions provide alternate periods of light and dark. Unrealistically high or low levels of moisture. In some applications, weathering reference materials are used to establish aetm of the operating conditions in an exposure test.
Results from accelerated exposure tests conducted according to this standard are best used to compare the relative performance of materials. Note astm g151 use of an y151 factor is desired in spite of the warnings given in adtm practice, such g511 factors for a astm g151 material are only valid if they are based on data from a sufficient number of separate exterior and laboratory accelerated exposures so that results used to relate times to failure in each exposure can be analyzed using statistical methods.
Reproducibility of test results between laboratories has been shown to be good when the stability of materials is evaluated in terms of performance ranking compared to other materials or to a control;therefore, exposure of a similar material astm g151 known performance a control at the same astn as the test materials is strongly recommended.
Test conditions where specimens are exposed continuously to light when actual use conditions provide alternate periods astm g151 light and dark. Acceleration factors calculated based on the ratio of astm g151 between a laboratory light source and solar radiation, even when zstm bandpasses are used, do not take into consideration the effects on a material of irradiance, temperature, moisture, and differences in spectral power distribution astm g151 the laboratory light source and solar radiation.
Therefore, even if results from a specific exposure test conducted according to astmm practice are found to be useful for comparing the relative durability of materials exposed t151 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.
Specific information about methods astm g151 determining the property of a astm g151 material before and after exposure are found in standards describing the method used to measure each property. 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 GGGand G respectively.
Information regarding the reporting of results from exposure testing of plastic materials is described in Practice D Detailed information regarding procedures to be used for specific devices are found in standards describing the particular device being used. Acceleration factors calculated based astm g151 the ratio of irradiance between a laboratory light source and solar radiation, even when identical bandpasses astm g151 used, do not take into consideration the effects on a material of irradiance, temperature, moisture, and differences in spectral power distribution between the laboratory light source and solar radiation.
Even though it is very tempting, calculation of an acceleration factor relating x h or megajoules of radiant exposure in a laboratory accelerated astm g151 to y months or years of exterior astm g151 is not recommended.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. An example of a astm g151 analysis using multiple laboratory and exterior exposures to calculate an acceleration factor is described by J. Reference materials, for example, blue wool test fabric, also astm g151 be used for the purpose of timing exposures.
Referenced Documents purchase separately The documents listed astm g151 are referenced within the subject standard but are not provided as part of the standard. For example, detailed information astm g151 exposures in devices that use carbon-arc, xenon-arc, and fluorescent UV light sources are found in Practices G, G, and G, and G respectively.
This information is intended primarily for producers of laboratory accelerated exposure devices. Guide G provides information for astm g151 of statistics to exposure test results Note 3—This standard is technically equivalent to ISOPart 1. Active view current version of standard. Exposure conditions that produce unrealistic temperature differences between light and dark colored astm g151.
Variability in the rate of degradation in both actual use and laboratory accelerated exposure test can have a significant effect on the calculated acceleration factor. Practices GGand Gand G are performance based standards that replace Practices, and.
Link to Active Astm g151 link will always route to the current Active version of the standard. Hemispherical on 37 Tilted Surface. Information regarding the reporting of astm g151 from exposure testing of plastic materials is described in Practice D In addition, it astm g151 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.
Astm g151 information about methods for determining the property of a nonmetallic material before and after exposure are found in standards describing the astm g151 used to measure each property. Note 2—Guide G provides information for astm g151 variability in exposure testing of nonmetallic materials.
Work Item s – proposed revisions of this standard. Results can be expressed by comparing the exposure time or radiant exposure necessary to change a characteristic property astm g151 some specified level. The test material then is evaluated. Exposure conditions that do not have any temperature cycling or that produce temperature cycling, or thermal shock, or both, that is not representative of use conditions.
There are a number of factors that astm g151 decrease the degree of correlation between accelerated tests using laboratory light sources and exterior exposures. Acceleration factors are material dependent and can be significantly different for each material and for different formulations of the same material. Specimen temperatures higher than those in actual conditions. ASTM Committee G3 is developing a standard guide for application of statistics to exposure test astm g151.