GMR and eddy current sensor in use of stress measurement

Abstract

The use of high sensitive magnetic sensors like magnetoresistive sensors allows novel applications in non-destructive testing (NDT), i.e. monitoring the conditions of reinforced concrete constructions. Using novel magnetoresistive sensors, a stress measurement of prestressed steel bars in concrete is realizable. The giant magnetoresistive sensor (GMR sensor) and the eddy current sensor are introduced here for high sensitive stress measurement. The combination of the eddy current technique with the magnetoelastic stray field measurement basically improves the mechanical stress measurement.