Contactless Determination of a Permanent Magnet’s Stable Position within Ferrofluid

Abstract

The paper deals with the contactless detection of a rod permanent magnet’s position within a ferrofluid. The working principle of the proposed approach is grounded on the solenoidal nature of the field lines. For the line detection technique analyzed in this article, where the magnetic field is scanned along the line parallel to the magnet’s axial direction, the center of the magnet corresponds to the point on the line where the radial component of the magnetic field vanished. The concept introduced here was evaluated numerically, where the results showed a promising perspective for the technique to be employed in practice. In contrast to the X-ray or Vernier-caliper-based technique, the one proposed here is somewhat more suitable for employment in applications where simplicity and robustness are of vital importance.

Keywords

• permanent magnet
• levitation
• ferrofluid
• magnetic sensor
• magnetic field
• finite element method (FEM)