7 General Maintenance
To Clean the EI XTR Source
7000/7010 Series TQ GC/MS Operating Manual 175
.
Procedure
1 If the contamination is serious, such as an oil backflow into the analyzer,
seriously consider replacing the contaminated parts.
2 Abrasively clean the surfaces that contact the sample or ion beam.
Use an abrasive slurry of alumina powder and reagent-grade methanol on a
cotton swab. Use enough force to remove all discolorations. Polishing the
parts is not necessary; small scratches will not harm performance. Also
abrasively clean the discolorations where electrons from the filaments
enter the source body.
If insulators are dirty, clean them with a cotton swab dampened with
reagent-grade methanol. If that does not clean the insulators, replace them. Do
not abrasively or ultrasonically clean the insulators.
The filaments, source heater assembly, and insulators cannot be cleaned
ultrasonically. Replace these components if major contamination occurs.
Figure 55. EI XTR source parts to be cleaned
Entrance lens
Ion focus lens
Extractor lens
Repeller block
insert
Source body
Repeller
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