ASTM G Standard Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-Metallic Materials. ASTM G Standard Practice for Operating Xenon Arc. Light Apparatus for UV Exposure of Nonmetallic Materials. View on Information Provider website. Engaged Expert Terry Candlish discusses ASTM G and G tests which are used to evaluate sunlight and moisture exposure. ASTM.
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Remember, these accelerated weatherization tests cannot exactly reproduce outdoor conditions, as they cannot account for altitude, seasonal variations, local geographical features, and other variables. Prior to exposing the specimens, quantify the appropriate properties in accordance with recognized international standards. Test results can be expected to differ between exposures using xenon arc devices in which the spectral power distributions differ by as much as that allowed by the tolerances.
ASTM G and G Explained | Element
Use of this equation requires that each spectral interval must be the same for example, 2 nm throughout the spectral region used. Set astmm 6 operational? Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. As such, the ASTM G and G tests produce comparative, not absolute data, but aastm comparative evaluations can still prove extremely valuable to designers.
Costs for weatherization testing will vary according g1555 a number of factors, including moisturization, sample size, number of cycles, and more. Generally, degradation processes accelerate with increasing temperature.
When comparing relative spectral power distribution data to the spectral power distribution requirements of this standard, use the rectangular integration technique. Appendix X1 lists some representative exposure conditions. Moisture takes its own toll on surfaces, and the combination of sunlight and xstm can amplify damage, costing millions of dollars of depreciation each year.
The spectral irradiance for a xenon arc with extended UV? The apparatus described in Practice G 26 iscovered by this practice. Exposures are not intended to simulate the deterioration caused by localized weather phenomena, such as atmospheric pollution, biological attack, and saltwater exposure. Our Engaged Experts can help you select the best UV bulbs for your testing purposes.
The pH of the water used should be reported. The length of dark period is not speci? Make an inquiry today. As a general guide, hours under UV-B bulbs is equivalent to 1 year of exposure in South Florida, while hours under UV-A bulbs can create the same exposure effects. Interruptions to service the apparatus and to inspect specimens shall be minimized. Y155, this test involves 21 days g1555 exposure. To assure uniform exposure conditions,?
Typically, these exposures would include moisture in the form of humidity. Masking or shielding the face of test specimens with an opaque cover for the purpose of showing the effects of exposure on one panel is not recommended.
E Previous versions of this standard used window glass? In contrast, UV-A bulbs have a propensity for accelerating color fading and yellowing. Therefore, no reference shall be made to results from the use of this practice unless accompanied by a report detailing the speci? Contact the manufacturer of the xenon-arc devices for speci?
These exposures may include a means to introduce moisture to the test specimen. In the ASTM G test, xenon arc lamps simulate full-spectrum sunlight within a controlled test chamber. For any individual xenon-lamp with window glass? However, each of these variables brings uniquely inaccurate results. This data is provided for comparison purposes only. Historical Version s – view previous versions of standard.
D The benchmark solar radiation data is de? Hemispherical on 37 degree Tilted Surface. For instance, a slight shift in formula may produce twice as much resistance to weathering. Cycle 8 corresponds to the test cycles speci? This is because test specimens having varying colors and thicknesses may be expected to vary in temperature.
Any backing used may affect test results and shall be agreed upon in advance between the interested parties. From environmental and dynamic testing to highly specialized tests such as bird strike and hydrodynamic ditching testing, we’re the trusted testing partner to the world’s most recognized component and system manufacturers.
ASTM G154 and G155 Explained
NOTE 3—Evaluation of color and appearance changes of exposed materials must be made based on comparisons to unexposed specimens of the same material which have been stored in the dark. Last previous edition approved in as G — The specimen temperature permissible for the accelerated test depends on the material to be tested and on the aging criterion under consideration.
See Practice D for detailed guidance. Historical convention has established Cycle 1 as a very commonly used exposure cycle. ASTM International recommends that a comparable material of identified performance a control be exposed at the same time as the test specimen.
If the actual operating conditions do not agree with the machine settings after the X3. See Appendix X4 for more information comparing the solar radiation data used in the standard with that for CIE 85 Table 4. Include a control, to act as a weatherization standard. A superscript epsilon e indicates an editorial change since the last revision or reapproval. At the operational control point, the operational?
B The data in Table 1 are based on the rectangular integration of spectral power distributions for water and air cooled xenon-arcs with daylight? Ultimately, the most realistic way to test for weathering is to allow the product to degrade in real time, with outdoor testing panels.