Inductive transducers with magnetic fluids

Inductive transducers are considered, which have as essential components electrical coils partially filled with magnetic fluid. It is shown that the displacement of the magnetically permeable liquid core of relative height t of a pair of identical coils produces an inductance difference Δ L( t) = L( t) - L(1 - t), which has a practically linear dependence on t for enough small values of the radius-to-length ratio of the coils. A design algorithm has been applied to construct various laboratory transducer models for inclination angle (from 0–2 to 0–200 arcmin), differential pressure (from 0–2 to 0–200 mm H 2O) and volumetric flow rate (from 0–3 to 0–10 5 1/h), whose resolutions attain 1 arcsec, 1 μm H 2O and 12 cm 3/h, respectively.