Cleaning The Source Ceramic And Focus Plates - Waters GCT Premier Operator's Manual

Cleaning the source ceramic and focus plates

During use, sample builds up on the source ceramics and on the focus plates
causing the leakage of extraction voltage and adversely affecting mass
accuracy and sensitivity. If voltage leakage occurs, the source must be
removed from the source lid assembly, disassembled, and the dirty
components individually cleaned.
If the emitter fails due to electrical discharge in the ion source the emitter
wire can be subject to a high, short current–enough to vaporize the wire.
If you notice a leakage current of more than 10 mA, this indicates a dirty
source.
To clean the focus plates:
1. In the MassLynx Tune window, click
into standby.
2. Vent the source and wait for the vacuum LED to go yellow.
3. Remove the outer source lid assembly from the instrument.
See also:
4. Place the outer source lid assembly on a bench so that the front support
plate is at the top.
5. Make a diagram of where the wires and gas tubing are located.
Rationale:
6. Unscrew and remove the two hex-head screws that secures the front
support plate to the outer source lid.
7. Loosen the remaining two hex-head screws, to allow the outer source
assembly to tilt back.
Removing the FI/FD outer source on page
This diagram aids assembling the outer source.
to switch the instrument
9-6.
FI/FD outer source maintenance 10-45