Meaning and use
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. Therefore, 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

Radius
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

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

Note 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.

Note 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 – Values expressed in SI units should be considered standard values. No other units of measurement are included in this standard.

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 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.

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 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.