Ferrite permanent magnet PM1055

neodymium-iron-boronsamarium-cobaltcylindrical

Metrolab’s permanent dipole magnets are serious scientific instruments, in a deceptively small and elegant package. Available in fields from 0.01 to 0.5 T, they are remarkably compact, weighing just around a kg and measuring 80 mm in diameter and 39 mm (0.01 – 0.27 T) or 55 mm (0.5 T) high. The magnetic field: more than meets the eye Depending on the strength required, we use Ferrite, Samarium-Cobalt, or Neodymium-Iron-Boron as core material. The pole face diameter is 50 mm, and the gap is 13 mm. The unique pole shape and gap adjustment allow us to create a 12 mm uniform region, capable of accepting NMR probes. In spite of such tight requirements in an incredibly compact package, our design allows for two large openings (32 mm x 14 mm) for accessing the gap, as well as a small fringe field. NMR stabilization All permanent magnets are sensitive to temperature. The strength of the core material itself decreases with increasing temperature, and thermal expansion changes the pole gap and therefore the field. PM1055 magnets include an auxiliary coil to offset all drift and to provide a perfectly stable field. If you stabilize the magnetic field with an NMR teslameter, the PM1055 becomes an ultra-compact reference magnet, stable to within a few parts per million.