Ferrite cores as back yoke for enhancing hall sensor sensitivity in caliper tool for pipeline inspection

Abstract

PurposeThe purpose of this paper is to describe how to improve magnetic pick up sensor for detection of weak magnetic field. A magnetic marker detection system, built using hall sensors is improved by providing ferrite cores as back yoke to obtain benchmarked performance with reduced number of hall sensors in an equipment for pipeline inspection called caliper tool.Design/methodology/approachThe paper opts for an exploratory study by making various configurations of sensors possible under given constraints, analyzing results of each one of them and correcting the configuration.FindingsInstead of using highly sensitive hall sensors, one can increase the sensitivity of sensor by putting simple ferrite core as back yoke in order to detect weak magnetic field.Originality/valueThis paper fulfils the need of detection of weak magnetic field by changing field direction and maximizing field component in direction of sensitive axis of magnetic sensor.

Analysis of Electromotive Force Characteristics for Electromagnetic Energy Harvester using Ferrofluid

“…Configuration of closed magnetic circuit increases the amount of magnetic flux linkage passing ferrofluid by changing the operating point of the permanent magnet. This method is frequently used to increase the magnetic flux for magnetic sensor system [7,8]. Use of back yoke is necessary because the amount of magnetic flux generated by energy harvester is small.…”