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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Link to Active This link will always route to the current Active version of asym standard. Comparisons between materials are best made when they are tested at the same time in the same exposure device.
In some cases, a reference material is exposed at the same time as a test material and the exposure is conducted until there is a defined change in property of the reference material. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of adtm standard. Results can zstm expressed by comparing the exposure time or radiant exposure necessary to change a characteristic property to some specified level.
Reference materials, for example, blue wool test fabric, also may be used for the purpose of timing exposures. Work Item s – proposed revisions of this standard.
Hemispherical on 37 Tilted Surface. In some cases, the results for the test material are compared to those sstm the reference material.
Exposure conditions that produce unrealistic temperature differences between light and dark colored specimens. The moment new editions of the standards you monitor are released, changes are made, or appendixes are published, you will be alerted by email.
In some applications, weathering reference materials are used to establish consistency of the operating conditions in an exposure test. More specific information on how each factor may alter stability ranking of materials is given in Appendix X1.
The test material then is evaluated. The benefits of a subscription: 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. Test conditions where specimens are exposed continuously to light when actual use conditions provide alternate periods of light and dark.
Note Guide G provides information for addressing variability in exposure testing of nonmetallic materials.
Results from accelerated exposure tests conducted according to this standard are best used to compare the relative performance of materials. This service is not available if you are a URL user where you do not log in with an email address.
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. These are inappropriate uses of reference materials when they are not sensitive to exposure stresses that produce failure in the test material or when the reference material is very sensitive to an exposure stress that has very axtm effect on the test material.
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.
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. This information is intended primarily for producers of laboratory accelerated exposure devices. 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 astk in devices that use carbon-arc, xenon-arc, and fluorescent UV light sources are found in Practices G, G, and G, and G respectively. No laboratory exposure test can be specified as a total simulation of actual use conditions in outdoor environments. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine asrm applicability of regulatory limitations prior to use.
ASTM Committee G3 is developing a standard guide for application of statistics to exposure test results. 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. 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.
ASTM G | Rycobel
Therefore, even asstm results from a specific exposure test conducted 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. 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 qstm using laboratory light sources and exterior exposures.
Work Item s – proposed revisions of this standard. 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. You need to log in before adding standards to the monitoring service.
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. 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 asrm exposure is not recommended. Exposure conditions that do aetm have any temperature cycling or that produce temperature cycling, or thermal shock, or both, that is not representative of use conditions.
A web subscription provides an easy and secure astmm to standards, and you are guaranteed to always have the latest edition. 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.