Atlas now offers the SEPAP 12/24, a medium-pressure mercury arc testing instrument. This accelerated photoaging device examines the photodegradation mechanisms of polymeric formulations in laboratory conditions. Designed as an analytical tool to understand the degradation mechanisms of naturally aging polymers at the molecular level, the SEPAP 12/24 unit replicates the chemical changes in accelerated, controlled lab conditions that are achieved through long-term, natural weathering conditions and from which similar changes in macroscopic properties (mechanical, aesthetical, etc.) can be expected.

SEPAP 12/24's design relies on the fundamental concepts of macromolecular photochemistry. The units are built as parallelepiped chambers with four medium-pressure mercury arc lamps in borosilicate envelopes that emit discrete radiation at 290, 313, 365, 405, 436, 547, and 579 nm. The light source is not used to simulate daylight, but to induce the same photochemical processes as daylight. Samples are homogeneously exposed on a rotating support in the center of the chamber. The surface temperature of the samples is accurately controlled and maintained between 50 and 80°C ±1°C through a thermocouple placed behind a reference film with the same color and chemical composition as the exposed samples.

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