IEC 60793-1-42:2013 establishes uniform requirements for measuring the chromatic dispersion of optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes. This third edition cancels and replaces the second edition, published in 2007. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - the inclusion of category B6 single-mode fibres; - the deletion of test method D (interferometry). Keywords: chromatic dispersion of optical fibre This publication is to be read in conjunction with IEC 60793-1-1:2008.