Direct Weathering means that the products under test are exposed with no physical barrier between the specimen and the sun, such as a layer of glass.
All DWS direct exposures meet the requirements of
ASTM G7 Standard Practice for Outdoor Exposure of Organic Materials unless otherwise specified by our customers.
Open Back Exposure:
Samples exposed on adjustable standard aluminum racks. Flexible samples can be backed with expanded metal for support without influencing sample temperature.
Samples exposed on adjustable standard aluminum racks with a backing of untreated plywood. The backing produces a higher temperature-testing environment that may be more be more representative of in use conditions.
Black Box Exposure:
The sample is mounted on a rack, which is backed by a mat- black painted aluminum box. Sunlight heats the air trapped inside the box, raising the temperature of the samples during the day. The black box can be angled according to customer requirements but is most commonly used at 5 degrees to the horizontal. This test is primarily used for automotive coatings, and other coatings that have to withstand a high-temperature end-use environment. All angles are available as requested.