This standard is issued under the fixed designation D ; the 1 This practice is under the jurisdiction of ASTM Committee D01 on Paint and. ASTM D Testing Water Resistance in % RH. Can be used to test the water resistance of coatings by exposing coated specimens to a high relative. ACCELERATED LIFE TESTING. Touchstone performs corrosion testing and accelerated life testing of virtually any material or device. Among the tests offered .
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It may be necessary to avoid placing specimens in the lower portion of the chamber as the temperature differentials at the lower levels may be too small to induce condensation. Air pressure to the humidifying tower should d22247 approximately 7 to 14 kPa 1 to 2 psi.
This standard has been approved for use by agencies of the U.
Other tests are used to monitor degree of failure as a function of exposure time. If condensation is not observed on any specimen immediately after the chamber is opened, discontinue the test and determine the cause of the lack of condensation before continuing.
Arrange specimens so that condensate from one specimen cannot drip on other specimens. Other tests may also deposit water droplets on the surface but where the source is not from condensation for example, water spray.
d22247 Specimens must be placed at a level above the water in the heating jacket to insure proper condensation. Best practice is to use two different control specimens, one with known relatively poor performance, and one with known relatively good performance. Evaluate specimens no less than 5 min and no more than 10 min after removal astmm test, as the effects from asfm exposure can change within a short time.
Note 1—Alternative practices for testing the water resistance of coatings include Practices DDand D A coating system is considered to pass if there is no evidence of water-related failure after a period of time. The substrate composition and surface preparation, specimen preparation, and astj number of specimens should be agreed upon prior to testing.
Other tests may also deposit water droplets on the surface but where the source is not from condensation. The minimum distance between adjacent test specimens shall be mm. Last previous edition approved in as D — Circulating fans should be used with caution as their use may reduce the temperature differential and limit condensation.
Practices D cover application techniques for the production of uniform? Operate the test continuously with the test chamber closed unless otherwise speci?
Corrosion atm can astn conducted, as the condensate dripping off the test articles in not recirculated. A coating system is considered to pass if there is no evidence of water-related failure after a period of time. Another option is to continue the test until all specimens have failed, and use the time to reach failure as a way to differentiate performance. Position 3-dimensional specimens on a support so that the primary surface is as close to end-use position as possible.
This makes this practice suitable for flat panels as well as large or 3D objects. The values given in parentheses are for information only.
If any specimen does not have condensation, or the condensation is present on only part of the specimen surface, the area within mm 4 in. It does not specify specimen preparation, or evaluation of results. Reverify the chamber astn there are any changes to the setup of the equipment or if any of the components listed in Section 5 are repaired or replaced.
The post-recovery rating allows evaluation of the permanent effects of the exposure as distinct from the transient effects, and is especially asfm for evaluation of color and gloss. Three types of apparatus have been found to meet the requirements of this practice.
Primary limit control for immersion heater 5 8—Water line 9—Insulation if necessary see X1. Corrosion tests can be conducted, as the condensate dripping off the test articles in not recirculated.
Water Resistance and Humidity (ASTM D 870, ASTM D 2247)
The use of a large heated water tank would tend to make the temperature within the chamber uniform, ast, thus inhibit or prevent the formation of condensate on the specimens.
The minimum distance between adjacent specimens or between specimens and the walls of the chamber shall be at least 30 mm. It does not specify specimen preparation, or evaluation of results. After the specimens have been wstm an unopened chamber for at least 12 h, open the chamber and check for the presence of uniform condensation on each specimen.
It does not specify specimen preparation, or evaluation of results. Such control specimens can provide warning of changes in test severity in a given apparatus, and can indicate variations in test axtm between different apparatuses. Asttm use of control specimens with known performance can also be used to determine the duration of the test that is required to produce meaningful results. Any effects such as color change, blistering, loss of adhesion, softening, or embrittlement are observed and reported.
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.