MAGNET CHARACTERISATION

	INTRODUCTION
	OPEN + CLOSE MAGNETIC CIRCUIT
	EDDY CURRENTS
	COMPARISON OF TECHNOLOGY USED IN MEASURING MAGNET CHARACTERISTICS

Introduction

The purpose of a magnetic characterising system is to determine the magnetic properties of a magnet or magnetic material. This information can be used for testing batches of all magnets in production, quality issues and research purposes.

The principles behind the technologies can be described as:-
“By applying a known magnetic field to a magnetic specimen, the applied field strength is monitoring against the specimen’s own magnetism (total flux) with the resultant changes being recorded for analysis”.

The magnetic characteristic is obtained by analysing the applied magnetic field and the sample’s own magnetism.

Although the principles are simple, it is the method of generating the applied field and measuring the magnets “magnetism” that differentiate between the various methods of measurement available, along with the limits to data available and the range each system can operate over.

Magnet characterising technologies include:

Before describing the above technologies in more depth, consideration needs to be given to two important factors in choosing a magnetic characterising technology namely, Open and Closed Magnetic Circuit Effect and Eddy Currents.

Next > Open + Closed Loop Effect

MAGNET CHARACTERISATION TECHNOLOGY COMPARISION TABLE

Click here to view the magnet characterisation comparison table.

The comparision table highlights at a glance the features of each technology used in the measurement of magnet sample characteristics

MAGNET CHARACTERISATION TECHNOLOGIES

Pulsed Field Magnetometry (PFM)

Pulsed Field Magnetometers apply a “pulse” of magnetic field to generate the applied magnetic field. This has the advantage that the field can be strong enough to saturate any magnetic material.

Vibrating Sample Magnetometry (VSM)

Vibrating Sample Magnetometers vibrate the sample as part of the measurement process. This provides the Fluxmeter element of the system with the dynamic component it requires to make the measurement. The applied field is changed so at each measurement point the field is static and hence no eddy currents to cause problems.

Permeameter Technology

Permeameters use a closed loop form of magnetic measurement.