New Types of Magnetoelastic Transducers for Sensing Force Related Parameters

A different perspective from which to view the operation of magnetoelastic force transducers is described. Unlike the more conventional approach based on the alteration of B-H loop shape by a stress dependent permeability, this perspective starts with the separate examination of the processes by which stress and magnetic field affect magnetization. The purpose of applying magnetic fields is identified as a useful means to observe the independent effects of stress. A transducer of novel construction, conceptually derived by a straightforward application of this perspective, is also described. The concept is supported by data obtained from experimental transducers employing permanent magnets and solid state field sensors in place of the conventional exciting currents and detection coils. The basic device can be readily configured as a transducer for axial, flexural or torsional loadings. The simplicity of the design encourages its use in the construction of small, low cost transducers for any force related parameter.