ASTM G155 PDF
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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To cool the lamp, distilled or deionized water is circulated over the burner tube and then directed out of the lamp between the inner and outer glass? F For the benchmark solar spectrum, the UV irradiance to nm is 9. When a standard calls for a particular set point, the user programs that exact number. Brass, steel, or copper shall not be used in the vicinity of the test specimens.
The set point is the target condition g1155 the sensor used at the operational control point as programmed by the user.
Annex A1 states how to determine relative spectral irradiance. Condensation may be produced on the face of the specimens by spraying the rear side of the specimens to cool them below the dew point. This practice is limited to the procedures for obtaining, measuring, and controlling conditions of exposure.
Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
It may be tempting to assume that shorter wavelengths, continuous exposure, high temperatures, and other variables can result in more intense acceleration.
When rays of sunlight—particularly UV rays—bombard a surface, they degrade smaller pigment particles, changing the surface color and creating a chalky effect. Positioning and calibration of chamber air temperature sensors shall be in accordance with the descriptions found in Practice G B The data in Table 3 are based on the rectangular integration of 81 spectral power distributions for water cooled and air cooled xenon-arcs with extended UV? When reproducibility in results from an exposure test conducted according to this practice have not been established through round-robin testing, performance requirements for materials shall be speci?
Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. At the operational control point, the operational? As such, the ASTM G and G tests produce comparative, not absolute data, but these comparative evaluations can still prove extremely valuable to designers. The round-robin shall be conducted according to Practice E or Practice D and shall include a statistically representative sample of all laboratories or organizations b155 would normally conduct the exposure and property measurement.
The specimen g515 permissible for the accelerated test depends on the material to be tested and on the aging criterion under consideration.
The percentages of UV and visible irradiances on samples exposed in xenon arc devices may vary due to the number and re? Following are some representative exposure conditions. Cycles 5 and 6 have been commonly used for indoor textile materials.
Refer to Practice G for full cautionary guidance applicable to all laboratory weathering devices. Misleading results may be obtained by asstm method, since the masked portion of the specimen is still exposed to temperature and humidity that in many cases will affect results. Thermometers shall conform to the descriptions found in Practice G More specific information about methods for determining the change in properties after exposure and reporting these results is described in Practice D Cycle 8 corresponds to the test cycles speci?
Maintain these conditions throughout the exposure. Due to time constraints, however, many producers employ the G and G laboratory chamber tests for reliable exposure results in shorter time periods.
ASTM G and G Explained | Element
See Practice G for further guidance. UV-B light accelerates the brittleness that materials, particularly polymers, may suffer as they age indoors. Filters to reduce irradiance at wavelengths shorter than nm must be used to simulate daylight?
This practice replaces Practice G26which describes very specific designs for devices used for xenon-arc exposures. Typically, these exposures would include moisture in the form of humidity. When required, provision shall be made for the spraying of asym on the test specimen, for the formation of condensate on the exposed face of the specimen or for the immersion of the test specimen in water.
This practice replaces Practice G 26, which describes very speci? Very low levels of silica in spray water can cause signi? See Practice G for detailed water quality instructions. The manufacturer is responsible for determining conformance to Table 3.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. It is recommended that at least three replicates of each material evaluated be exposed in each test to allow for statistical evaluation of g155.
ASTM G154 and G155 Explained
It is impossible to recreate nature in the lab. Element provides both types of tests at our ISO accredited testing laboratories. Typically, this is done at 2 nm increments. The spectral power distribution of xenon arcs with new or pre-aged? Originally approved in The type of thermometer used, the method of mounting on specimen holder, and the exposure temperature shall be stated in the test report.
In contrast, UV-A bulbs have a propensity for accelerating color fading and yellowing.
Consult the applicable test method or material speci? Different type and different size lamps operating in different wattage ranges may be utilized in different sizes and types of apparatus. If the asym operating conditions do not agree with the machine settings after the X3. For any individual xenon-arc lamp with extended UV? The minimum satm maximum data are at least the three sigma limits from the mean for all measurements. Link to Active This link will always route to the current Active version of the standard.
Cycle 8 has been used for automotive interior components.