The Single/Dual Enclosed Carbon Arc has been in use for the laboratory artificial testing of materials since 1918. Many accelerated fading tests require the enclosed carbon arc. The device features carbon rods and a Pyrex 9200px glass globe which surrounds the arc and filters out energy below 280nm. Test materials are mounted on a single rack that rotates around the lamp three times per minute. The unit has controls for black panel temperature and humidity.

Several large "spikes" of energy in the ultraviolet portion of the spectrum between 360 and 420 nm can cause samples to deteriorate rapidly, but not necessarily in agreeement with natural weathering. The carbon arc is very widely used in the USA and many specifications in major industries such as textile and interior automotive still require this device. Methods include ASTM G23 Type A and Type D, AATCC 16, and JIS 0205.
At Sub-Tropical we use the Atlas Model 18-F. This is a more advanced instrument than the typical "space-ship" unit developed in the 1940's. The 18-F features the same light source and spectral power distribution as the earlier unit but has additional controls. These newer controls produce more repeatable results by regulating temperature and humidity. The 18-F also has redesigned air flow and the addition of a humidifier and humidity chamber which provides more consistent and uniform distribution of air throughout the test chamber. Also important is the redesigned temperature regulation system.
Historically, the enclosed carbon arc system was originally used to light movie studios in the 1920's. Studio employees first noticed the increased fading of studio props such as curtains and linens. This lead to this light sources development as the first accelerated fading device. It was originally used to test only fabrics but today this unit is employed in the testing of almost any material which undergoes degradation by light, heat, and moisture.

Home/Outdoor Weathering/Accelerated Weathering/Miami, FL Site/Surprise, AZ Site/List of Services/Evaluations/Exposure Testing/Exposure Form/Quarterly Newsletter/Meet the Staff/Contact Sub-Tropical Testing/