משמעות ושימוש
5.1 The device exposes the specimen to light, heat and optional moisture, typically attempting to replicate the changes in specimen characteristics observed in both outdoor and indoor end-use environments. Exposure is not intended to simulate deterioration caused by local weather phenomena such as atmospheric pollution, biological attacks, and salt water exposure.

5.2 This practice allows for a wide range of exposure conditions that may produce significantly different results. לָכֵן, the results of its use should not be referred to unless accompanied by a report in section 10 detailing specific operating conditions.

5.2.1 Controls (similar materials with known properties) should be exposed at the same time as the sample to provide a reference for comparison purposes. It is better to use two different control materials: one known to have relatively poor durability and the other known to have relatively good durability. Each sample and control material should be repeated at least three times at the same time for statistical evaluation of the results.

ASTM G155-2021 Practice for Xenon Arc Lamp Equipment for Exposure of Non-Metallic Materials

5.3 Results obtained from specimens exposed in different devices (even if the device is of the same model) using the same set point and operational controls should not be compared unless repeatability of the material to be tested has been established between devices.

5.4 Please refer to Practice G151 for warning guidelines applicable to all laboratory aging equipment.

5.5 Users are advised to follow good laboratory practices to reduce exposure variability (1). 8

רַדִיוּס
1.1 This practice is limited to the basic principles and procedures for operating xenon arc lamps and water installations; By itself, it does not provide specific results.

1.2 It is intended to be used in conjunction with practices or methods that define specific exposure conditions for applications and methods for assessing changes in material properties. This practice aims to reproduce the weathering effects that occur when materials are exposed to sunlight (directly or through window glass) and moisture (such as humidity, rain, or dew) during actual use. This practice is limited to procedures for obtaining, measuring, and controlling exposure conditions.

ASTM G155-2021 Practice for Xenon Arc Lamp Equipment for Exposure of Non-Metallic Materials

הערה 1: A number of exposure procedures are listed in the appendix; למרות זאת, this practice does not specify the appropriate exposure conditions for the material to be tested.

הערה 2: Practice G151 describes the general procedures and performance requirements used when exposing materials in equipment that uses laboratory light sources.

1.3 Under controlled environmental conditions, the sample is exposed to light from an optically filtered xenon arc lamp. The combinations of different types of filters and xenon arc sources are described.

1.4 Sample preparation and result evaluation are covered in ASTM methods or specifications for specific materials. General guidance is given in Practice G151.

הערה 3: General information on methods for determining post-exposure changes in properties and reporting these results is described in Practice D5870.

1.5 This practice does not apply to corrosion testing of bare metals.

1.6 Units – ערכים המבוטאים ביחידות SI צריכים להיחשב כערכים סטנדרטיים. אין יחידות מדידה אחרות כלולות בתקן זה.

1.7 This practice is technically similar to the following ISO documents: ISO 4892-2, ISO 16474-2, ISO 105-B02, ISO 105-B04, ISO 105-B05, ISO 105-B06 and ISO 105-B10.

ASTM G155-2021 Practice for Xenon Arc Lamp Equipment for Exposure of Non-Metallic Materials

1.8 תקן זה לא נועד לתת מענה לכל חששות הבטיחות, אם בכלל, הקשורים לשימוש בו. באחריות המשתמשים בתקן זה לבסס בטיחות מתאימה, שיטות בריאות וסביבתיות ולקבוע את תחולתן של הגבלות רגולטוריות לפני השימוש.

1.8.1 If the operation of the lamp produces any ozone, it should be removed from the sample and the operator through the exhaust system.

1.9 תקן בינלאומי זה מבוסס על עקרונות תקינה מוכרים בינלאומיים שנקבעו בהחלטה על עקרונות לפיתוח תקנים בינלאומיים, הנחיות והמלצות שהונפקו על ידי ועדת ה-WTO בנושא חסמים טכניים לסחר.