Meaning and use
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. Therefore, 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.

Note 2: For additional information on sources of variability and strategies to address variability in the design, execution, and data analysis of laboratory accelerated exposure tests, see Guide 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 Therefore, it is strongly recommended to expose similar materials with known properties (controls) at the same time as the test material. 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

Radius
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 Values expressed in SI units shall be regarded as standard values. The values given in parentheses are for reference only.

1.3 This standard is not intended to address all safety concerns, if any, associated with its use. It is the responsibility of users of this standard to establish appropriate safety, health and environmental practices and to determine the applicability of regulatory restrictions prior to use.

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

1.4 This international standard is based on internationally recognized standardization principles established in the Decision on Principles for the Development of International Standards, Guidelines and Recommendations issued by the WTO Committee on Technical Barriers to Trade.