Magnetoelastic resonance sensor for remote strain measurements.

A low cost passive wireless strain sensor is proposed. The basis of the sensor is formed by two softmagnetic magnetostrictive ribbons. The first magnetostrictive ribbon transforms mechanical stress into a stress dependent magnetic field. The second ribbon senses this field by magnetoacoustic oscillations. The resonance frequency directly depends on the applied mechanical stress. For the proposed sensor, a gauge factor Gf, which is defined as the relative change of the resonance frequency divided by the strain &eh;, of Gf = 380 is obtained. This is significantly higher than the gauge factor of standard metal foil strain gages. [ABSTRACT FROM AUTHOR]