15
4.2 Non-ferrous specimens (using vacuum table version)
1. Ensure that the rubber vacuum sealing ring is clean and is securely fitted
into the groove. Place the specimen onto the vacuum table ensuring that
the specimen covers the rubber vacuum sealing ring (Figure 10). The edge
of the specimen should be no closer than 10 mm from the vacuum sealing
ring; the minimum non-ferrous specimen size is therefore 140 mm x 80 mm
(5.5" x 3.1").
Figure 10. Specimen mounted on vacuum table
2. Maintenance of sealing ring. Clean with non-aggressive solvent and
lubricate with neutral vaseline.
3. When working with small specimens with coatings which require a lot of
force to scratch, it may be necessary to insert spacers between the stop
blocks and the specimen to prevent the specimen from slipping (Figure 11).
Figure 11. Spacers between specimen and stop blocks
4. Rotate the vacuum on/off control clockwise to switch on the vacuum and
secure the specimen.
5. Now scratch (See Section 7).
Op_1535_01 A5.fm Page 15 Wednesday, August 8, 2007 3:59 PM
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