2000 MS Hardware Maintenance
40
Chemical Ionization Options
•
Note the
Diffusion Pump Foreline Pressure
reading under the Vacuum
System field. The reading should be less than 100 mTorr. Higher
readings may indicate problems (i.e., leaks) and the user should refer to
the
Troubleshooting
section
for additional information. Click on the
Manual Control button, and then click the CI icon to the left of the ion trap
symbol (it will turn green when On). Wait one minute for the flow to
equilibrate. Click on Diagnostics and note the
Diffusion Pump Foreline
Pressure
reading. The value should be less than 350 mTorr. If
necessary, adjust the delivery pressure of the CI reagent gas (using the
valve on the pressure regulator) to give a reading below 350 mTorr. If
the value exceeds 500 mTorr the diffusion pump will shut down. It will
restart when the pressure drops below 500 mTorr.
The Liquid CI Inlet Option
You may review the installation and use of the Liquid CI Inlet on the Saturn 2000
Maintenance Tutorial CD. Alternatively, you may read the instructions that follow
in this section.
Installation of the Liquid CI Inlet
1. Before beginning, shut down and vent the Saturn system. If you are not
disassembling the trap, it is not necessary to wait for the trap electrodes to
cool down before installing the Liquid CI Inlet assembly.
2. Remove the top cover. Attach the Liquid CI Inlet assembly to the back of the
instrument using the following instructions. Refer to the drawings below to
more easily identify the parts discussed.
a. From the back of the instrument, remove one of the two screws that hold
the CI shutoff block intact. Replace it, loosely, with a long screw
supplied with the kit (12-222006-25).
b. Remove the remaining screw.
c. Gently pull the free end of the liquid CI restrictor tube (03-930024-01)
from the L-bracket where it attaches to the back of the instrument, while
leaving the other end of the restrictor tube attached to the Liquid CI Inlet
block.
