Summary This article presents the design of dual observers for lumped-and distributed-parameter systems. The resulting compensator is of finite order for both system classes. Consequently, dual observers can be designed for distributed-parameter systems on the basis of the separation principle. For this problem a parametric approach is proposed. The presented results are illustrated by determining a finitedimensional dual disturbance observer for a heat conductor that asymptotically rejects sinusodial disturbances.Schlagwörter Lineare konzentriert-und verteilt-parametrische Systeme, dualer Beobachter, Störgrößenaufschaltung, Störbeobachter Keywords Linear lumped-and distributed-parameter systems, dual observer, disturbance feedforward control, disturbance observer 1 Einleitung