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GMW Dipole Electromagnet, 45mm, 3470 


3470 45 mm Electromagnet shown with tapered poles fitted
3470 with hall probe mount.
Please visit our Magnet Systems page for
more information.

3470HFAC AC Electromagnet, dc to 25kHz

 Small Size
 Reversible Plane or Tapered Poles
 Adjustable Pole Gap
 Air or Water Cooled
 Adjustable Coil Spacing
 Bench or Wall Mounting
 Optional 50mm Square Poles

 Hall Effect Studies
 Magneto-Optical Studies
 Laboratory Experiments
 Magnetic Separation experiments
 Magnetic alignment of small components
 Studying chemical reaction rate changes

The 3470 Electromagnet is the smallest and lightest standard dipole electromagnet available from GMW.  It is used in a wide range of teaching, research and industrial applications where a relatively small volume of field is required.  The light weight allows it to be used on optical tables and the simple poles enable axial entry & exit holes to be matched to the optical geometry. 

The electromagnet has two 45mm (1 ¾ inch) diameter cylindrical pole pieces. One end of each pole piece has a plane cylindrical 40mm pole face and the other end has a tapered 20mm pole face. The 40mm pole face produces the most uniform field. The tapered 20mm pole faces are used when higher gap fields are needed. Each pole piece is clamped in the yoke by a bolt. The pole pieces are adjusted to vary the gap by slackening the clamping bolts. The same procedure is used to remove or reverse the pole pieces. The gap is adjusted in the range from 0 to 75mm. Optional square poles (50mm side) are available. (The square poles have been applied in a simple mass spectrometer as described in "Undergraduate Mass Spectrometer", John W. Dewdey, American Journal of Physics, 28 (1960) 452-456.

The two coils are wound on spools, which have integral, electrically isolated, water cooling tubes and overtemperature interlock switches. Operation with water cooling allows a maximum coil current of 6A. Regular tap water may be used. Without water cooling, the maximum operating current is 3.5A. The coil-to-coil spacing is adjustable over the range from 35 to 75 mm.

Variation and Customizations

  • 3470HFAC High Frequency AC Magnet. Fields to ±70MT with frequency from dc to 25kHz
  • 3470-ET “Extended Throat” has a 165mm deep throat [from center of pole face to yoke cross-bar] sized to apply field to the center of a 300mm wafer.
  • Custom Yoke geometries (e.g. extended air-gap)
  • Custom poles optimized for field uniformity, physical access to sample, and optical access to sample.


  Tel: + 650-802-8292    Fax: + 650-802-8298
955 Industrial Road, San Carlos, CA 94070, USA