Stray field demagnetizer

Stray field demagnetizing devices with a flux amplifying core are usually called plate, tabletop or surface demagnetizer. The parts to be treated are demagnetized over the core by the stray field. Two pole plates are additionally used to the flux amplifying core in the case of the plate demagnetizer, which strongly bundle the stray flux in the region of the pole gap.

Mode of operation

The magnetic stray field is the field portion which runs on the outside of a coil or a flux-conducting material. The stray field decreases strongly with increasing distance from the field source. Demagnetizing devices with a stray field principle are thus successfully used for demagnetizing flat objects of low wall thickness. On the other hand, the comprehensive magnetic fluxing of voluminous components is only possible to a limited extent.

Field lines surface demagnetizer
Field lines surface demagnetizer

The devices used by Cestriom GmbH are operated either directly at the mains in a continuous process or with power modules in pulsed or continuous mode.

Standard surface demagnetizers

The surface demagnetizers (without pole plates) used by Cestriom GmbH cover an effective width range between 160mm and 600mm. Other dimensions on request.

The standard surface demagnetizers are connected to the mains frequency 230VAC or 400VAC, 50/60Hz.

Surface demagnetizer
Surface demagnetizer with working width 250mm

Demagnetizer machine with surface type coil

Power modules LM enhance the functionality to the level of an industrial demagnetizer machine.

Manual operation:

Demagnetization occurs by placing the object on the surface demagnetizer and pressing the pulse button on the power module. A controlled demagnetizer is a very safe device for the operator (personal protection related to electromagnetic fields). The pulse function enables demagnetization without the need of moving the parts through the electromagnetic field of the coil. As a supplementary technological feature, demagnetizing pulses can be programmed in a way to comply much better with personal protection limits (in comparision to standard 50Hz mains frequency demagnetizers).


These Demagnetizer machine units are easy to automate. Communication with higher-level control is done via interface. The configuration of the optimal demagnetization process is done in consultation with Cestriom GmbH.

Surface demagnetizer with power module LM14
We design specific variants for your needs

Technological functions:

  • Demagnetization by high field strength sine pulse.
  • Continuous pulse demagnetization.
  • Continuous demagnetization with low frequency for more penetration depth.
  • Use of two surface demagnetizers (double yoke).
  • Demagnetization by very short pulses (~1’000ms).
  • Monitoring functions.