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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A coating system is considered to pass if there is no evidence of water-related failure after a period of time. 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. Referenced Documents purchase separately The documents listed below are d2274 within the subject standard but are not provided as part of the standard.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. 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.
This standard has been approved for use by agencies of the U. One type uses a water tank with an sstm immersion heater, another uses a water vapor generator, and the third type uses a submerged air distribution pipe. 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 is difficult to produce condensation with small chambers because the temperature differential is too slight. Other tests are used to monitor degree of failure as a function of exposure time. This makes this practice suitable for flat panels as well as large or 3D objects.
Rate specimens for changes in color, blistering, etc. Short interruptions to inspect or remove specimens are permitted, but such interruptions should occur no more than once each day.
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. Some tests are used for a pass or fail determination at an arbitrary time. Three types of apparatus have been found to meet the requirements of this practice. Primary limit control for immersion heater 6 5—Heated water tank for supplying heat and humidity to room 6—Immersion heater 7—Water temperature limit control 8—Constant level water tank unheated with over?
Operate the test continuously with the test chamber closed unless otherwise speci?
Last previous edition approved in as D — Link to Active This link will always route to the current Active version of the standard. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. Another aastm is to continue the test until all specimens have failed, and use the time to reach failure as a way to differentiate performance.
The post-recovery rating allows evaluation of the permanent effects of the exposure as distinct from the transient effects, and is especially important for evaluation of color and gloss. As the warmer saturated air passes the cooler specimens, water is deposited onto the specimens in the form of condensation.
The use of a f2247 heated water tank would tend to make the temperature within the chamber uniform, and thus inhibit or prevent the formation of condensate on the specimens. Such control specimens can provide warning of changes in test severity in a given d247, and can indicate variations in test severity between different apparatuses. Evaluate specimens no less than 5 min and no more than 10 min after removal from test, as the effects from water exposure can change within a short time.
The saturated mixture of water vapor and air temperature rises and then cools below the aetm point, causing condensation on the specimens.
If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below.
This practice differs from other methods where condensation is only formed on the front coating surface, while the back surface is outside the exposure area. Material used for supports shall be of sufficient stiffness so that they do not distort or sag during prolonged use. This practice differs from other methods where condensation is only formed on the front coating surface, while the back surface sstm outside the exposure area.
Water Resistance and Humidity (ASTM D 870, ASTM D 2247)
Air pressure to the humidifying tower should be approximately 7 to 14 kPa 1 to 2 psi. Some tests are used for a pass or fail determination at an arbitrary time.
Link to Active This link will always route to the current Active version of the standard. Another option is to continue the test sstm all specimens have failed, and use the time to reach failure as a way to differentiate performance.
A number in parentheses indicates the year of last reapproval. As the warmer saturated air passes the cooler specimens, water is deposited onto the specimens in the form of condensation.
The minimum distance between adjacent test specimens shall be mm. This practice differs from other methods where condensation is only formed on the front coating surface, but the back surface is outside the exposure area.