Characterisation of magnetic materials via a pulsed, field strength variable magnetic field transmitter and a sensor with eddy current component removal
US5565774A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1995 |
| Grant date | Oct 15, 1996 |
| Priority date | — |
| Expiry date | May 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
High-energy permanent magnetic materials are characterized by exposing the material to sequential pulsed fields of respectively different rates of change of magnetic field strength, sensing the total magnetic field strength, sensing the total magnetic field generated in the sample by the respective pulses including eddy currents induced therein, and eliminating eddy current components from the said fields, whereby the net magnetic fields relate to the magnetic characteristics of the sample. Preferably the pulsed field is capacitor-generated via a solenoid and the rate of change of the magnetic field strength is produced by holding the waveform constant and altering the pulse duration, for example by providing taps on the solenoid together with an inductor and a balancing resistor, to enable the ratio of resistance to inductance to be maintained substantially constant across the range of taps utilized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.