Betekenis en gebruik
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, biologische aanvallen, en blootstelling aan zout water. Caveat – Within the accepted limits of this practice, changes in operating conditions do not necessarily provide the same results. Daarom, 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.

Opmerking 2: Voor aanvullende informatie over bronnen van variabiliteit en strategieën om variabiliteit in het ontwerp aan te pakken, executie, and data analysis of laboratory accelerated exposure tests, zie geleider 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 Daarom, it is strongly recommended to expose similar materials with known properties (controles) tegelijkertijd met het testmateriaal. 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

Straal
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 Waarden uitgedrukt in SI-eenheden worden als standaardwaarden beschouwd. De waarden tussen haakjes zijn alleen ter referentie.

1.3 Deze norm is niet bedoeld om alle veiligheidsproblemen aan te pakken, indien aanwezig, die verband houden met het gebruik ervan. Het is de verantwoordelijkheid van de gebruikers van deze norm om de juiste veiligheid te garanderen, gezondheids- en milieupraktijken en om vóór gebruik de toepasbaarheid van wettelijke beperkingen vast te stellen.

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

1.4 Deze internationale norm is gebaseerd op internationaal erkende standaardisatieprincipes die zijn vastgelegd in het Besluit over de beginselen voor de ontwikkeling van internationale normen, Richtlijnen en aanbevelingen uitgegeven door het WTO-comité voor technische handelsbelemmeringen.