To achieve an appearance-retention rating, a carpet undergoes rigorous testing to determine appearance changes produced by foot traffic over defined periods of time. Using a Hexapod or Vetterman Drum, the test mechanically simulates various levels of foot traffic over a carpet sample. After the carpet is tested, appearance changes are assessed and a retention rating value is assigned. CRI’s Appearance Retention Rating Scale does not gauge variable factors such as soiling, staining, maintenance, and installation.
The new use-classification system indicates the minimum carpet rating that should be recommended for a particular area. The classification determines the value, expressed on a scale of 1 to 5, that is needed according to CRI’s Appearance Retention Rating Scale. Most carpet specified for use in severe traffic conditions should meet or exceed the Appearance Retention Rating of 4.5 over the short term and 3.5 long term.