ASTM G – 00 Standard Practice for Exposing Nonmetallic. Materials in Accelerated Test Devices that Use Laboratory. Light Sources. View on Information. ASTM G UV EXPOSURE (GENERAL). This practice provides general procedures to be used when exposing nonmetallic materials in accelerated test. 21 Jun ASTM G – Designation: G – 09 Standard Practice for Exposing Nonmetallic Materials in Ac.
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Detailed information regarding procedures to be used for specific devices are found in standards describing the particular device being used. This service is not available if you are a URL user where you do not log in with an email address. Test conditions astj specimens are exposed continuously to light when actual use conditions provide alternate periods of light and dark.
ASTM G – UV EXPOSURE (GENERAL)
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 of known performance a control at the same time as the test materials is strongly recommended.
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. For example, detailed information covering exposures in devices that use carbon-arc, xenon-arc, and fluorescent UV light sources are found in Practices G, G, and G511, and G respectively.
Note 5—Definitions for control and reference material that are appropriate to weathering tests are found in Terminology G 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. In some cases, the results for the test material are compared to those for the reference material. Acceleration factors calculated based on the ratio of irradiance between a laboratory light source and solar radiation, even when identical bandpasses are 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.
Therefore, even if results from a specific exposure test conducted aatm 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 ast the same materials for a different environment.
No laboratory exposure test can be specified as a total simulation of actual use conditions in outdoor environments. Results from accelerated exposure tests conducted according to this standard are best used to compare the relative performance of materials.
Exposure conditions that produce unrealistic temperature differences between light and dark colored specimens. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Note 1—Carbon-arc, xenon arc, and fluorescent UV exposures were also described in Practices, and which referred to very specific equipment designs.
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.
ASTM Committee G3 is developing a standard guide for application of statistics to exposure test results. Link to Active This link will always route to the current Active version of the standard.
When conducting exposures in devices that use laboratory 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.
Note 6—Practice G describes procedures for selecting and characterizing weathering reference materials used to establish consistency of operating conditions in a laboratory accelerated test. Practices GGand Gand G are performance based standards that replace Practices, and.
Work Item s – proposed revisions of this standard. This information is intended primarily for producers of asrm accelerated exposure devices. Monitoring Standards monitoring is a free service designed for you who wish to be alerted of changes to or new editions of the standards required in your work.
Information regarding the reporting of results from exposure testing of plastic materials is described in Practice D More specific information on how each factor may alter stability ranking of materials is given in Appendix X1. Standards monitoring is a free service designed for you who wish to be alerted of changes to or new editions of the standards required in your work.
There are a number of factors that may decrease the degree of correlation between accelerated tests using laboratory light sources and exterior exposures. Results can be expressed by comparing the exposure time or radiant exposure necessary to change a characteristic property to some specified level.
Detailed information regarding procedures to be used for specific devices are found in standards describing the particular device being used.
Guide G provides information for application of statistics to exposure atsm results. Link to Active This link will always route to the current Active version of the standard. The test material then is evaluated. Techstreet standards in subscription. Note Guide G provides information for addressing variability in exposure testing of nonmetallic materials.
ASTM G | Rycobel
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. Comparisons between materials qstm best ast when they are tested at the same time in the same exposure device.
Note 4—If use of an acceleration factor is desired in spite of the warnings given in this practice, such acceleration factors for a particular 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.
If you need to be able to add standards to the monitoring service, you must register as a user with your own username and password. Variability in the rate of degradation in both actual use and laboratory accelerated exposure test can have atsm significant effect on the calculated acceleration factor.
These acceleration factors are not valid for several reasons. Guide G provides information for application of statistics to exposure test results Note 3—This standard is technically equivalent to ISOPart 1. 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 property.
Note 2—Guide G provides information for addressing variability in exposure testing of nonmetallic materials. A web subscription provides an easy and secure access to standards, and you are guaranteed to always have the latest edition. A g15 application is conducting a test to establish that the level of quality of different batches does not vary from a control material with known performance. Asm moment new editions astn the standards you monitor are released, changes are made, or appendixes are published, you will be alerted by email.