Design of a capacitive displacement-measuring system for vertex detectors at colliding beam machines

We describe the design of capacitively based systems to monitor as a function of time the relative positions of silicon detectors for the Mark-II and Delphi experiments with respect to other elements of the detectors. We present data from tests of the systems for the Mark-II and Delphi detectors which show that such a system can track all movements to a level of 5 μm or less. (orig.)