Abstract
Fluxset magnetic sensor based probes with single and double exciting coils have been developed for detecting weakly interacting, low mass and small size magnetic particles. Test measurements were performed on capsules containing 0.15–13.53 mg magnetic iron oxide particles. It was shown that even 0.7 mg of magnetic nanoparticle of size 30 nm could be detected from a distance of 3.5 mm with reliable signal to noise ratio.