A survey is given of the theoretical background for designing multi-terminal capacitor sensors of several types, suitable for control of every physical quantity that can be related with the change in position of two carriers, covered with electrodes. Previously published investigations of capacitor sensors, are briefly mentioned, and a description of the capacitance bridge used and the results of investigations of a multi-terminal capacitor test model are given. The main conclusion is that the capacitor sensors described can be used in cases where reliability and sensitivity of laser interferometry and strain gauge measurements fail.