The Telecommunications Industry Association has published a new standard on fiber optic test procedures. The document provides a method of measuring residual twist in optical fiber ribbons and highlights critical aspects of this measurement. The residual twist is a measure of how much a ribbon rotates or twists along a given length. Residual twist results from the ribbon manufacturing process or from changes in the dimensions of a ribbon because of aging from heat and humidity. Excessive residual twist can hinder splicing.