Hardware manual

4-90 Agilent 7500 Series ICP-MS Hardware Manual
4Maintenance
7 Test the electrical resistance of this compound lens with an Ohm meter
before continuing.
Ensure continuity between the Omega bias (front) and Omega bias
(back), QP focus (front) and QP focus (back), and the base plate and
spacer 3. Also ensure that there is no continuity between the base plate
(ground) and each electrode.
2 Attach the Einzel Lens - Omega lens assembly into the instrument.
Remove the vacuum chamber cover. Put the Einzel lens- Omega lens
assembly in the vacuum chamber as shown in Figure 73. Insert the Einzel
lens 1 into the wall hole on the sampling cone side.
Firmly tighten Screw 1 to fix the lens assembly to the vacuum chamber.
Then, tighten (two) Screw 2 firmly to fix the print board to the lens
assembly.
3 Pump Down the System.
See “Working Inside the Vacuum Chamber” earlier in this chapter.
Refitting the Extraction Lenses
The extraction lenses are circular with notches in the perimeters. To reattach
the lenses and fit them back into the instrument, complete the following steps:
1 Reattach the extraction lenses.
Use Figure 72 to correctly orient each piece when reassembling the
extraction lenses onto the skimmer base. Then tighten each Screw 2.
Ensure that there is no continuity between the skimmer base (ground) and
each leader electrode.
2 Place the extraction lens assembly in the instrument.
Tilt the extraction lens assembly vertically. Place the lens assembly through
the interface into the cavity outside the vacuum chamber. Align the top hole
with the guide pin.
3 Attach the extraction lens assembly to the instrument.
Adjusting the holes to the shaft on the body side and tightening (three) of
Screw 1 with an Allen wrench. If the extraction lens assembly fails to form a
seal with the interface chamber, operating vacuum pressures will not be
achieved.
4 Reattach the cone.
See “Maintaining the Cones” earlier in this chapter for information on how
to screw the cones into the instrument.