New electromagnetic transducers for recording translations and vibrations

The paper discusses new instrumentation developed for measuring translations and vibrations of mechanical parts. Electromagnetic fields are employed for these measurements, and mechanical loading is, therefore, avoided. At first one-sided capacitive transducers are treated. Secondly, differential capacitive transducers are discussed. An electronic method is investigated by which the operation of such differential bridges can be maintained linear even if the deviation of the moving member from its central position was large. The last parts of the paper deal with microwave interferometric bridges. It is shown that movements of remote objects with amplitudes in the micrometer region can be recorded from distances of several meters.