Because the relative humidity within museums fluctuates, paintings upon wooden supports shrink and swell. A new automatic system, which allows simultaneous measurements at 60 different places on a wooden panel, was used for monitoring the dimensional changes of a panel in Gemäldegalerie Berlin-Dahlem, from September 1988 to June 1989. This preliminary test demonstrated that the panel responded dimensionally to relative humidity changes immediately. In future work, the investigations will analyze dimensional changes as a function of panel size, wood species, and the age of the wood.