Abstract: A transducer designed to give an output which is dependent upon the relative displacement of two bodies comprises two sets of spaced plates interleaved one with the other to form a capacitor, the two sets of plates being movable relative to each other in a direction which maintains the spacing between them, the shape and or disposition of the plates being such that when an oscillating voltage is applied across the capacitor an output signal derived from an intermediate plate varies with changes in the position of the two sets of plates.Such an arrangement gives an output which is substantially linearly dependent on displacement, and by attaching one set of plates to some form of spring the device can be used as a force transducer.