Standards require current emblems to be visible at 600 feet. But experts don't believe that's far enough. The orange fluorescent center portion of new SMVs will last longer. The photo below illustrates the difference in fluorescent materials used in SMVs. Materials from several manufacturers were put through a durability test by South Florida Testing Service.
Most farmers are familiar with the telltale pattern of a failing SMV emblem.
The center turns yellow, then white. Betty Thorp of SMV Technologies, Odessa, Florida, explains that as fluorescent material deteriorates, it loses its unique ability to reflect more visible light than strikes it. It absorbs nonvisible energy and emits it at wavelengths which can be seen, causing it to appear to glow in the daylight. Online SF Online Copyright Meredith Corporation 1996. All rights reserved.