DEMAGNETISERS

	INTRODUCTION
	PRINCIPLES OF DEMAGNETISATION
	TYPES OF DEMAGNETISING SYSTEMS
	MECHANICAL HANDLING

Types of Demagnetising Systems

Hirst Magnetic Instruments manufactures five types of demagnetising systems each suitable for a particular type of application.

The type of demagnetiser chosen will depend mostly on the type of material to be demagnetised and the effects of any surrounding material on the demagnetisation process.

The required maximum magnetisation level will also determine the type i.e. how much magnetic strength is acceptable after demagnetisation.

AC Demagnetiser

AC Demagnetisers are suitable for small, low field demagnetisation, i.e. cathode ray tubes and certain steel applications.

These are the simplest of demagnetisers. A coil or demagnetisation fixture is connected to a mains supply that may or may not be controlled by electronics to control the magnetic field’s magnitude. For the smallest and simplest of cases a hand held AC demagnetiser may be used.

Either the fixture is moved away from the work piece, or the work piece is moved away from the static fixture. Either way the resultant demagnetisation is very dependent upon the speed of relative movement. If this relative movement is made by an operator, then the efficiency of the demagnetisation process can be seriously impaired.

Resonant AC Demagnetiser

A variation on a mains demagnetiser is to incorporate a resonant technique to offer higher fields with low continuous input current. Dependent on the application, this can achieve effective demagnetisation without the need for component removal from the demagnetising location.

This technique can be adopted for small and large applications.

Capacitive Discharge Demagnetising Systems

Hirst Magnetic Instruments Ltd. offer capacitive discharge demagnetising systems suitable for demagnetising permanent magnet materials as individual components or as part of an assemblies.

These techniques can be used to demagnetise individual parts or on mass depending on the application.

Capacitive discharge demagnetisers are the most popular form of demagnetiser.

Charging up a capacitor bank and discharging this energy into a demagnetising fixture can generate demagnetising fields much larger and can cover a much larger volume than AC and precision systems.

Hirst Magnetic Instruments incorporate microprocessor technology in their demagnetisers to safely manage the charging and discharging of the machine during the magnetising operation making it very safe to use.

Capacitive discharge systems can achieve high production rates and be part of an automated system with conveyor or other mechanical feeding systems.

The following describe the various capacitive discharge units with their appropriate features and applications.

MCSD Series Demagnetiser

The MCSD is the ideal general purpose machine where the ability to magnetise and demagnetise from a single unit is required. With the PLC connector and a serial port the ability to automate these units makes them very versatile.

The MCSD series has all the features of the MCD series plus the ability to apply set and magnetisation pulses. The MCSD can also apply reverse polarity pulses.

MD Series Demagnetiser

The MD range of demagnetisers is fully microprocessor controlled. The microprocessor also performs fault monitoring for system protection.

With the options to add PLC connections and RS232 serial port for external control and automation makes the MD range of demagnetisers very versatile.

Precision Demagnetiser PDM

Precision demagnetisers are used to achieve very accurate demagnetisation.

With this technique, a pre-programmed demagnetising wave form is generated. The frequency and decay timebase of the applied AC demagnetising field is accurately controlled. This is often required for components of a large mass.

Systems can be a single axis or two and three axis systems for the best demagnetisation processes.

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TURNKEY SOLUTIONS

Our approach objective is simple, total customer satisfaction. From initial consultation, through the design phase to manufacture and supply, Hirst will effectively manage the whole process making your "turnkey solution" a reality.

DEMAGNETISER PRODUCT RANGE
	MCSD Series Demagnetiser The ideal general purpose machine where the ability to magnetise and demagnetise from a single unit is required
	MD Series Demagnetiser The MD range of demagnetisers is fully microprocessor controlled
	AC Demagnetiser Suitable for small, low field demagnetisation
	PDM Precision Demagnetiser Are used to achieve very accurate demagnetisation.

CHOOSING THE RIGHT SOLUTION

To help us provide the best solution for your demagnetising application, we have prepared a short on-line questionnaire. Please view this questionnaire to enable us to provide a quick response to your requirements.