Electric current measurement using AMR sensor array

Anisotropic magnetoresistive sensor can be used to measure DC and AC current by sensing the field near the conductor in a contactless way. In order to improve measurement accuracy, an analysis of the influence of the displacement of the examined wire is made. According to the result of the analysis, restriction on the displacement of the examined wire is given. Current measurement method based on current carrying wire position estimation is presented. Experimental results show that current measurement method based on current carrying wire position estimation is of higher accuracy than that of direct summation method. For example, for sensor circular of 25.4 mm radius around the measurement hole of 10 mm radius, the maximum relative error of wire position estimation method due to non-concentric wire is about 0.2%.