A Mechanical Impedance Bridge
Anton Wiggins · The Journal of the Acoustical Society of America · 1943
The mechanical impedance bridge consists of two identical cantilever reeds clamped to a driving mechanism which can be driven electrically at various frequencies. Conventional condenser microphone amplifiers are used to measure the relative displacements of the reeds from their neutral positions. From the values of the relative displacements of the reeds, with one reed loaded with an unknown mechanical impedance, the value of the mechanical impedance may be calculated.