Systematic optimization of the sensing properties of ring-core fluxgate sensors with different core diameters and materials

• Published in: Sensors and actuators. A. Physical. 2017-03, Vol.255, p.94-103
• Main Authors: Can, Hava, Svec, Peter, Bydzovsky, Jan, Sözeri, Hüseyin, Topal, Uğur
• Format: Article
• Language: English
• Subjects: Alloy systems; Amorphous metallic core; Annealing; Cobalt; Cobalt base alloys; Design parameters; Fluxgate magnetometers; Fluxgate noise; Fluxgates; Magnetic induction; Magnetism; Magnetometer; Magnetostriction; Optimization; Sensors
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2017.01.013

•Optimization of sensing properties of ring-core fluxgate sensor was realized.•The optimal core diameter and the core materials were assigned in the examined series of cobalt based amorphous sof magnetic materials.•Finding appropriate annealing route for the sensor cores, the noise level of ∼1pT/√Hz @1Hzandthesensitivityoflargerthan1MV(*)/T was reached. In this study, a series of cobalt-riched alloy compositions Co71-xFexCr7Si8B14 (x=0, 2.0, 3.2, 4.0, 6.0 and 8.0) in the form of ribbons were produced to change magnetization characteristics and constants of magnetostriction in a controllable manner. In this way dominant parameters for the design of low-noise fluxgate sensor were determined. The studies were carried out in ring-core geometry for different diameters from 6mm to 20mm. Our experiments have shown that low values of the saturation magnetic induction Bs inherent for this alloy system had a crucial role for the noise level. With the cores having Bs of ∼0.4T, we could achieve a noise level of ∼1pT/√Hz @ 1Hz. The specific features of design of the ring-core fluxgates having different dynamical ranges were also discussed thoroughly. The ring-core diameter of 15mm was found to be optimal geometry for outdoor applications.