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发表于 2012-4-9 20:53:17
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ASTM B117& q9 g3 N* k: Y2 ?+ a
Test Conditions
$ K* A' b5 W2 z3 Y9 s9 Z, i4 ^) @: }& b wTest durations) \- t3 E: {7 d$ S% V a
Test durations are typically in 24-hour increments and can range from 24 hours to 5000 hours (where salt fog exposure is a part of a more complex test method, exposure time can be as little as 15 minutes.) Except for sample rotation and daily monitoring of collection rates, the cabinet should remain closed for the duration of the test. l% x' g- V2 O3 a7 q+ x% ?
Appendix X.3! l q. s7 M3 [$ R- Z1 `& W* ^
In 1987, Appendix X.3 was added to ASTM B117 to suggest the use of mass loss panels as a means for checking the corrosive conditions in a given salt spray chamber. The procedure calls for SAE 1008 commercial grade cold-rolled carbon steel panels, measuring 76 x 127 x 0.8 mm, to be cleaned, weighed, and placed in the chamber in the proximity of the collector funnels. After an exposure time of 48, 96, or 168 hours, the panels are removed, cleaned, and re-weighed. When conducted on a regular basis, the final mass loss number can be used as a tool for monitoring consistent corrosive conditions within the chamber. The frequency of conducting this test should be determined by the user, but common practice suggests the test be conducted monthly, or whenever any change occurs which might affect the cabinet - such as a change of location, salt, water, operators, etc.9 A/ x1 H3 R d4 u
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