A Noninvasive Current Measurement Technique Using Magnetic Sensors for Concealed Conductors

In this article, we present an innovative noninvasive current measurement technique utilizing magnetic sensors (MSs). Our proposed technique, comprising a current probe and an interface circuit, ensures precise MS orientation and positioning during current measurements on conductors. The current probe houses five MSs strategically positioned for minimal conductor access, while the interface circuit processes sensor output to optimize probe alignment. These distinctive features enable accurate current measurements even on concealed or inaccessible conductors, such as those positioned behind walls. To validate the efficacy of our approach, we designed and constructed a portable handheld current probe along with the interface circuit and conducted comprehensive laboratory testing. Comparative analysis with a standard current measurement system demonstrated our system’s accuracy. Across a current range of 0–15 A, we achieved an observed accuracy within ±0.84% with a resolution of approximately 0.04 A. Notably, within the 5–10-A range, the system exhibited enhanced accuracy of ±0.56%. Moreover, the proposed design’s versatility allows for seamless adaptation to various current ranges, enabled by the selection of MSs with specific sensitivities.