Electrode Cleaning On Pdhid - Scion Instruments 436-GC Service Manual

436-GC/456-GC

ELECTRODE CLEANING ON PDHID

The PDHID discharge electrode can become coated with oxidized material with extensive use.
The following steps should be taken to clean the electrode. These steps should be taken when
the sensitivity of the system begin to decrease to the point where the desired results are
effected. Therefore, it is important that a standard is run periodically to determine that sensitivity
is adequate. The cleaning should be done as seldom as possible.
Tools required:
Cleaning steps:
SCION Instruments
1) ¼" special spanner wrench (CP740760)
2) ¼" wrench
3) 600 grit emery cloth
4) Methanol
5) De-ionized water
(Handle electrode with care)
1) Turn the PDHID pulser voltage off.
2) Use both wrenches to remove the electrode from the top of the PDHID.
It is imperative that a backup wrench be used when removing the
electrode. Failure to do so will result in not repairable damage to the
detector.
3) Use the emery cloth to polish the oxidized material off the electrode.
4) Wash the electrode in Methanol.
5) Wash the electrode in De-ionized water.
6) Replace the electrode back in the detector. Be sure to use a backup
wrench when tightening the electrode in place.
436-GC/456-GC Service Manual Revision B February 2019
810 Preventive Maintenance
Page: 183