BS ISO 19862:2015 pdf download – Buildings and civil engineering works — Sealants — Durability to extension compression cycling under accelerated weathering.
5.10? Fully? automated? artificial? weathering? test? chamber? with? an? artificial? light? source, fully automated test chamber with an artificial light source (see 5.11), shall be used, capable of exposing the test specimens to radiation under controlled conditions of temperature, relative humidity, and water, complying with the requirements of ISO 4892-1, ISO 4892-2, ISO 4892-3, and ISO 4892-4. The radiation is always directed towards the same surface of the sealant specimen. Standard practices for operating such accelerated weathering chambers are described in ISO 4892-1. The level of irradiance and water exposure at the specimen surface may not be altered. In fully automated test equipment, exposure to water for this test method is accomplished by water spraying the specimen surface or immersing the test specimens in water (see Note 1 and Note 2). Contamination of the water is to be avoided. The purity of the water to be used is described in ISO 4892-1. The water temperatures are typically (21 ± 5) °C for the spray water and typically (40 ± 5) °C for the re-circulated immersion water (see Note 3). Suitable equipment and test procedures for cyclic exposures to water are described in ISO 4892-1, ISO 4892-2, ISO 4892-3, and ISO 4892-4. Water is a key factor contributing to the ageing of sealants, especially in combination with exposure to light. In xenon arc devices that use water spray for wetting, relative humidity during the light period shall be maintained at (50 ± 10) % RH, (see ISO 4892-2:2013, Table 3, Method A, Cycle Number 1) (see Note 4). In the immersion technique, the test specimens are placed in a chamber that is periodically flooded with re-circulated water. During immersion, the specimens are completely covered by water. The water temperature is measured below the water surface with the black standard thermometer. The immersion spray water can be at a higher temperature.