For demagnetizing whole machines and units of larger dimensions, other techniques are used than stationary coils. For these applications, portable or mobile demagnetizers with magnetic field cables have proven to be effective.
The components to be demagnetized are wrapped with the magnetic field cables, or the magnetic field cable wound into a coil is placed on the relevant part surfaces.
Cestriom GmbH uses a low-frequency alternating field demagnetization method (below 1Hz) and a precise field control technology. The demagnetization with low frequency reduces eddy currents and thereby causes high penetration depth of the magnetic field into ferromagnetic material.
Brochure portable demagnetizer MGFE-70 (pdf)
Characteristics:
- High power capacity: up to 30’000 Ampère turns (At) with 4 magnetic field cables
- Demagnetization by low frequency alternating field sine pulse
- Magnetization by controlled DC field sequences
- Special magnetic field functions for advanced applications
- Very high repeatability and comprehensive setting options of the field control
- Flexible, shielded magnetic field cables in different lengths and cross sections
- Use of coils of the SSM series with MGFE-70
- Mobility: Suitcase on wheels, weight about 22kg
- Power requirements: Three-phase 3×380…480VAC 50 / 60Hz 32A or 16A (reduced at 16A power)
Applications:
- Non-destructive testing: in particular magnetic particle testing (MT) and eddy current testing (ET)
- Rotating equipment: demagnetization of shafts, bearing seats, housings, preparation for condition monitoring tests with eddy current. Reducing residual magnetism induced shaft voltage.
- Mechanical engineering and tool making: demagnetizing of tools, machine parts, etc.
- Steel trade, Suppliers: Demagnetization to comply with residual magnetism limits
- Welding: Demagnetization as process preparation before welding
- R&D, special applications: various applications
Example of an operational device:
