[3] Displacement sensors can be used to indirectly measure a number of other quantities, including deformation, distortion, thermal expansion, thickness (normally through the combination of two sensors), vibration, spindle motion, fluid level, strain and mechanical shock.
[1] Displacement receivers can be used to study and observe the stress waves passing through a material after it is struck.
[5] Optical displacement sensors exist, using reflected light to determine distance.
[6] Strain gauges can be used as the base for small displacement transducers on the order of 0 to 10 mm.
[citation needed] Examples of displacement-responding sensors include the mechanical action of tracker organs, as well as the force-sensing resistors found in music keyboards that had polyphonic aftertouch capability.