MicroCal VP-ITC User Manual page 81

Polishing a new plunger tip
After replacing a tip it will need to be polished to remove any high spots that may exist on the
Teflon plunger, due to the manufacturing process. To polish a new tip:
•
Ensure that the Guide Sleeve and Threaded Cap are in place.
•
Click on the Polish New Tip button. The injector screw should extend out ca. 1½ inch (ca.
40 mm) and be hidden by the Guide Sleeve. Carefully push the glass bore Polishing Tool
over the new plunger tip. Please note: the 250 µl glass bore Tip Sizer tool must align with
the pipette screw; the barrel must not be inserted at an angle as this may cause the
injector screw to bend.
•
Slowly and gently push the Tip Sizer tool back and forth over the new tip 10 to 20 times
(using care to keep the polishing aligned with the injector screw of the pipette). As the tip is
polished, it will travel in the glass bore more freely and less force will be required to 'break it
in'. A total of 30 to 50 strokes are usually required.
•
When you are finished remove the Tip Sizer tool.
•
Unscrew the Threaded cap and remove the Guide Sleeve.
•
Using cotton tipped applicators (dipped in methanol), small tweezers,
lint free paper towels and/or clean compressed air (or other clean gas),
clean the plunger tip carefully to remove any Teflon shavings, dirt or
other fibers from the plunger tip.
!
Caution: inspect the tip carefully to insure no extraneous fibers or
dirt is attached to the plunger tip before proceeding.
•
Click on the New Tip Polished button. The injector screw will retract
into the pipette.
•
While observing that the plunger tip is aligned with the bore of the
injector syringe, turn the Locking Collar to screw the Pipette injector to
the base to reassemble the pipette.
Section 5: Instrument Maintenance
71