Arti dan Tujuan
4.1 Air menyebabkan lapisannya rusak, so understanding how the coating is waterproof helps to evaluate its performance in practical use. Test failures at 100% relative humidity can be caused by a variety of factors, termasuk cacat pada lapisan itu sendiri, contamination of the substrate or inadequate surface treatment. Karena itu, this practice is very useful for evaluating the coating individually or the entire coating system.

4.2 Pengujian di 100% relative humidity for specification acceptance, quality control and research and development of coating and substrate treatment. Some tests are used to determine pass or fail at any time. If there is no evidence of water-related failure after a period of time, sistem pelapisan dianggap telah lulus. Other tests are used to monitor the degree of failure as a function of exposure time.

4.2.1 Arbitrary pass/fail levels and required test durations are typically set in other material specific test methods. Users who do this can use the known performance of the control to set the test endpoint. An alternative is to continue testing until all specimens fail and use the time to failure as a way of distinguishing performance.

4.3 Sampai relevansi kuantitatif dari sistem pelapisan atau pelapisan ditentukan, the results obtained using a 100% humidity test in accordance with this protocol should not be expressed as equivalent to a period of exposure to water in the natural environment.

4.4 The test room may be a small laboratory cabinet or a room large enough to accommodate a car or truck. Some automakers test complete vehicles in a room that maintains 100 percent relative humidity. Corrosion tests can be carried out because the condensed water dripping from the test item will not be recirculated.

ASTM D 2247-2020 “Penentuan Ketahanan Air Pelapis pada 100% Kelembaban relatif”

Ruang lingkup
1.1 The practice covers the fundamentals and operating procedures for testing the water resistance of a coating by exposing the coated specimen to an atmosphere maintained at 100% relative humidity in order to form condensation on all surfaces of the specimen.

1.2 This practice uses techniques that create a slight temperature difference within the exposed area in order to form condensation on the coated specimen. When the hotter saturated air passes through the cooler sample, water is deposited on the sample in the form of condensation.

1.3 This practice places the entire specimen in the exposed area, allowing condensation to form on all surfaces. This makes the practice suitable for tablets as well as large or 3D objects. This practice differs from other methods in that only condensation forms on the front coated surface and the back surface is outside the exposed area. Other tests may also deposit water droplets on the surface, but the source is not from condensation (Misalnya, spraying water).

Catatan 1: Alternative practices for testing paint for water resistance include D870, D1735 and D4585.

1.4 Praktek ini terbatas pada metode memperolehnya, measuring and controlling the conditions and procedures of tests performed at 100% kelembaban relatif. It does not specify specimen preparation or outcome evaluation.

1.5 Nilai yang dinyatakan dalam satuan SI harus dianggap standar. Nilai yang diberikan dalam tanda kurung hanya untuk referensi.

ASTM D 2247-2020 “Penentuan Ketahanan Air Pelapis pada 100% Kelembaban relatif”

1.6 Standar ini tidak dimaksudkan untuk mengatasi semua masalah keselamatan, jika ada, terkait dengan penggunaannya. Pengguna standar ini bertanggung jawab untuk menetapkan keselamatan yang sesuai, praktik kesehatan dan lingkungan dan untuk menentukan penerapan pembatasan peraturan sebelum digunakan.

1.7 Standar internasional ini telah dikembangkan sesuai dengan prinsip-prinsip standardisasi yang diakui secara internasional yang ditetapkan dalam Keputusan Prinsip-Prinsip Pengembangan Standar Internasional, Pedoman dan Rekomendasi yang dikeluarkan oleh Komite Hambatan Teknis Perdagangan Organisasi Perdagangan Dunia.