Magnetic Field Distribution and Design of Helmholtz Coils
Abstract
A uniform magnetic field is required to calibrate magnetic induction sensor coils. Two types of coil designs are considered; a single finite length solenoid and a coaxially split coil pair (Helmholtz coil). The design must be able to reliably predict the magnitude of the calibration field and its homogeneity, both radially and axially, to within certain tolerances. The experimental results of a design based on the split coil pair are given. Furthermore, it is suggested that the quasi-uniform field in the mid-plane of a split coil pair can be usefully extended by narrowing the gap of the conventional Helmholtz coil pair spacing. In such cases, the flux in a circular region in the mid-plane can approach the value that would exist for a perfectly uniform field because of the partial cancellation between fields greater than and less than the central field. The deviation of the central field from that of an infinitely long solenoid is also discussed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1991
- Accession Number
- ADA242978
Entities
People
- Julian Vrbancich
Organizations
- Defence Science and Technology Group