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5
General Maintenance
150
5975/5977 Series MSD Operating Manual
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.
3
Rinse away all abrasive residue with reagent-grade methanol.
Make sure
all
abrasive residue is rinsed
before
ultrasonic cleaning. If the
methanol becomes cloudy or contains visible particles, rinse again three times.
4
Separate the parts that were abrasively cleaned from the parts that were not
abrasively cleaned.
5
Ultrasonically clean the parts (each group separately) for 15 minutes. For
dirty parts, use all three solvents in the order shown, cleaning 15 minutes with
each of the following solvents:
•
Methylene chloride (reagent-grade)
•
Acetone (reagent-grade)
•
Methanol (reagent-grade)
For routine cleaning, cleaning with methanol is sufficient.
6
Place the parts in a clean beaker.
Loosely
cover the beaker with clean
aluminum foil (dull side down).
7
Dry the cleaned parts in an oven at 100°C for 5–6 minutes.
CAUTION
The filaments, source heater assembly, and insulators cannot be cleaned
ultrasonically. Replace these components if major contamination occurs.
WARNING
All of these solvents are hazardous. Work in a fume hood and take all
appropriate precautions.
WARNING
Let the parts cool before you handle them.
NOTE
Take care to avoid recontaminating cleaned and dried parts. Put on new, clean
gloves before handling the parts. Do not set the cleaned parts on a dirty
surface. Set them only on clean, lint-free cloths.