User`s manual

7800 Series Hysteresisgraph System User's Manual
C-4 Obtaining Measurement Repeatability
Pole-Tip Geometry and Condition (Continued)
3. Poletip cleaning methods
a. Poletips may be cleaned by using a piece of adhesive tape and drawing the adhesive side across the
poleface to attract and remove any residual particles on the poleface.
b. Care must be taken not to simply move the debris away from the poleface (say, on the edge of the pole) to
keep this material from being redeposited on the poleface.
4. When a significant amount of contamination or surface imperfection is present and cannot be cleaned by
conventional means, the poleface should be resurfaced.
a. This may be done with a surface grinder taking off as much material as needed to ensure a clean poleface.
b. For embedded pole coils, care must be taken to ensure that the embedded soils are not damaged when
resurfacing.
(1) Often, only a small amount of material may be removed from embedded pole coils before they are
damaged.
(2) Consult with the factory too see if they can be resurfaced and how much can be ground off.
c. When resurfacing poletips, note that Fe poles need to be kept oiled to be free from oxidation which leads
to rust on the polefaces.
d. Poletips may also be coated with Ni or other anti-rust coating to keep them from rusting.
e. FeCo poletips are rust resistant at standard temperature and humidity conditions and need not be coated
after resurfacing.