Earth current memory sensor for use in power distribution lines

This paper discusses an earth current memory sensor (for use in power distribution lines) that we have suggested, constructed and evaluated. The sensor employs a semi-hard magnetic material to record whether there has been an earth current in a given earthing conductor or not, and an amorphous magnetostrictive metal wire to retrieve the information stored in the memory (semi-hard material). So far we have achieved a sensitivity of 6 A. The sensor permanently stores the information of an earth current, making it possible to retrieve the information even long after the earth current has ceased. Furthermore, the sensor is fairly cheap to be viable for installation on each and every distribution line pole without significantly increasing the cost.