Význam a použití
4.1 Poměrně rychlé zhoršení chemického stavu, physical and mechanical properties of materials made from photodegradable plastics when exposed to light, heat and water after achieving their intended purpose. This practice is designed to cause changes in properties related to the conditions the material may encounter when discarded as garbage, including the effects of sunlight, vlhkost, 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.

4.2 Opatření – When operating conditions vary within the acceptable limits of this practice, results can be expected to change. Proto, reference to the use of this practice must not be made unless accompanied by a report prepared in accordance with section 9 describing the specific operating conditions used. For more information about the precautions that apply to using results obtained under this practice, see Practice G151.

Poznámka 2: For additional information on sources of variability and strategies to address variability in the design, execution, and data analysis of laboratory accelerated exposure trials, see Guideline G141.

ASTM D5208-2022 Standardní postup pro fluorescenční ultrafialové paprsky

4.3 Simultaneous exposure to similar materials with known properties (řízení) with the sample provides criteria for comparison purposes. The use of controls to rank the stability of test materials greatly improves consistency across different laboratories. It is recommended that at least three repetitions of the material for each evaluation be performed in order to statistically evaluate the results.

4.4 Test results will depend on the degree of care taken to operate the equipment in accordance with practice G154. Important factors include regulation of the line voltage, the temperature of the room in which the equipment is operating, regulace teploty, and the condition and age of the lamp (if exposed in equipment without irradiance control).

Poloměr
1.1 This procedure covers specific procedures applicable to fluorescent ultraviolet (UV) irradiation of photodegradable plastics in accordance with procedures G151 and G154. The practice also includes the preparation of test samples and the evaluation of test results.

1.2 Practice D4329 covers fluorescent UV exposure to plastics used for outdoor applications.

ASTM D5208-2022 Standardní postup pro fluorescenční ultrafialové paprsky

1.3 Hodnoty vyjádřené v jednotkách SI se považují za standardní hodnoty. Hodnoty uvedené v závorkách jsou pouze orientační.

1.4 Tato norma není určena k řešení všech bezpečnostních problémů, jestli nějaký, spojené s jeho užíváním. Je odpovědností uživatelů této normy zajistit odpovídající bezpečnost, zdravotní a environmentální postupy a určit použitelnost regulačních omezení před použitím.

Poznámka 1: There is no known ISO equivalent to this standard.

1.5 Tato mezinárodní norma je založena na mezinárodně uznávaných zásadách normalizace stanovených v Rozhodnutí o zásadách pro vývoj mezinárodních norem, Směrnice a doporučení vydané Výborem WTO pro technické překážky obchodu.