משמעות ושימוש
4.1 The ability of plastic materials to resist degradation caused by exposure to light, heat and water is of great importance in many applications. This practice is designed to induce performance changes related to end-use conditions, including the effects of ultraviolet solar irradiance, humidity and heat. The exposures used in this practice are not intended to simulate deterioration caused by local weather phenomena, such as atmospheric pollution, biological attacks, and salt water exposure. Caveat – Within the accepted limits of this practice, changes in operating conditions do not necessarily provide the same results. לָכֵן, reference to the use of this practice should not be made unless accompanied by a report describing the specific operating conditions used in accordance with section 8. Please refer to Practice G151 for more information on the precautions applicable to the use of results obtained under this practice.

הערה 2: למידע נוסף על מקורות שונות ואסטרטגיות לטיפול בשונות בעיצוב, ביצוע, and data analysis of laboratory accelerated exposure tests, ראה מדריך G141.

4.2 The reproducibility of test results between laboratories has been shown to be good when evaluating the stability of a material according to its performance class compared to other materials or controls. 5,6 לָכֵן, it is strongly recommended to expose similar materials with known properties (בקרות) במקביל לחומר הבדיקה. At least three repetitions of each material are recommended to enable statistical evaluation of the results.

4.3 Test results will depend on the degree of care taken to operate the equipment in accordance with practice G154. Important factors include the regulation of the line voltage, the temperature of the equipment working room, temperature control, and the condition and age of the lights.

ASTM D4329-2021 Standard Practice for Exposure of Fluorescent Ultraviolet (UV) Lamp Installations for Plastics

רַדִיוּס
1.1 This procedure covers specific procedures and test conditions applicable to exposure to plastics using fluorescent UV lamps and water equipment in accordance with practices G151 and G154. The practice also includes the preparation of the sample, the test conditions suitable for the plastic, and the evaluation of the test results.

1.2 ערכים המבוטאים ביחידות SI ייחשבו כערכים סטנדרטיים. הערכים המופיעים בסוגריים הם לעיון בלבד.

1.3 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.

הערה 1: This standard and ISO 4892-3 cover the same topic, but differ in their technical touch.

1.4 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.