Significato e uso
5.1 Il dispositivo espone il campione alla luce, calore e umidità opzionale, 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. Perciò, 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.

Pratica ASTM G155-2021 per apparecchiature con lampade ad arco allo xeno per l'esposizione di materiali non metallici

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

Raggio
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) e umidità (such as humidity, piovere, or dew) during actual use. This practice is limited to procedures for obtaining, measuring, and controlling exposure conditions.

Pratica ASTM G155-2021 per apparecchiature con lampade ad arco allo xeno per l'esposizione di materiali non metallici

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

Nota 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.

Nota 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 – I valori espressi in unità SI devono essere considerati valori standard. Nessun'altra unità di misura è inclusa in questo standard.

1.7 This practice is technically similar to the following ISO documents: ISO 4892-2, ISO 16474-2, ISO105-B02, ISO 105-B04, ISO 105-B05, ISO 105-B06 and ISO 105-B10.

Pratica ASTM G155-2021 per apparecchiature con lampade ad arco allo xeno per l'esposizione di materiali non metallici

1.8 Questo standard non è destinato ad affrontare tutti i problemi di sicurezza, se presente, legati al suo utilizzo. È responsabilità degli utenti di questo standard stabilire una sicurezza adeguata, pratiche sanitarie e ambientali e per determinare l'applicabilità delle restrizioni normative prima dell'uso.

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 Questo standard internazionale si basa su principi di standardizzazione riconosciuti a livello internazionale stabiliti nella Decisione sui principi per lo sviluppo di standard internazionali, Linee guida e raccomandazioni emesse dal comitato dell'OMC sugli ostacoli tecnici al commercio.