Signification et objectif
4.1 The procedures described in this specification are intended to assist in the evaluation of coating performance on a variety of metal panels, including new or rusted steel.

4.2 Due to differences in solar radiation, temps humide, température, polluants, et d'autres facteurs, the relative durability of paint during outdoor exposure may vary considerably depending on the location of the exposure. Donc, it cannot be assumed that the results of a single exposure at a single location will help determine the relative durability of different locations. Exposure is recommended at multiple sites with different climates that represent a wide range of expected service conditions.

4.2.1 Due to annual climate variability, the results of a single exposure test cannot be used to predict the absolute rate of material degradation. It takes several years of repeated exposure to obtain an “moyenne” test result for a given location.

4.2.2 Solar radiation varies greatly with the time of year. This can lead to large differences in apparent degradation rates for many polymers. It is not recommended to compare results for materials exposed for a short period of time (less than one year) unless the materials were exposed at the same location at the same time.

4.3 Meaning and Use of G7 in practice addresses many of the variables that need to be considered in external exposure testing. Guide G141 provides more information on variability in aging tests.

ASTMD 1014-2018 “Test d'exposition extérieure pour les peintures et revêtements menaçants sur des substrats métalliques”

Champ d'application
1.1 This practice covers the procedures to be followed when exposing external paints and coatings directly to metal surfaces. When the sponsor actual exposure of the aging test is carried out by a separate agency, the specific conditions for testing and controlling the exposure of the specimen should be clearly defined and mutually agreed upon by the parties.

1.2 Experience has shown that the metal used as a test substrate has a significant impact on weathering results. The aim of this practice is to define specific steel and other metal surfaces for testing in order to minimize this source of variability.

1.3 Les valeurs exprimées en unités SI doivent être considérées comme des normes. Les valeurs données entre parenthèses sont à titre indicatif uniquement.

1.4 Cette norme n'est pas destinée à traiter tous les problèmes de sécurité, si seulement, associé à son utilisation. Il est de la responsabilité de l'utilisateur de cette norme d'établir des mesures de sécurité appropriées., pratiques sanitaires et environnementales et pour déterminer l’applicabilité des restrictions réglementaires avant utilisation.

1.5 La présente Norme internationale a été élaborée conformément aux principes de normalisation internationalement reconnus établis dans la Décision sur les principes pour l'élaboration de normes internationales., Lignes directrices et recommandations émises par le Comité des obstacles techniques au commerce de l'Organisation mondiale du commerce.