Abstract: A technical roll, in particular for paper manufacturing, having an elongated roll core and at least one first covering which is provided on the roll core, wherein an empty duct or conduit is provided, which is suitable for receiving a polymer fibre and extends over the length of the roll such that the polymer fibre can be introduced at one end of the empty duct. The application also relates to a technical roll having a polymer fibre, to a method for introducing the polymer fibre into an empty duct, and to the use of a polymer-based optical waveguide as a sensor in a technical roll.