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D
Remove, clean, inspect for damage, grease, and reinstall the vacuum chamber lid
o-ring. Make sure the o-ring is not twisted.
D
Check the torque on fasteners between the bellows and arm base; see
section 5.3.4. Do not over-tighten these fasteners or new leaks can be created.
D
As an aid in identifying the source of the leak, place a few drops of isopropyl
alcohol on the suspected area and look for an observable change in the vacuum
gauge reading.
6.3.1.8 Will Not Achieve Less Than 10
-3
Torr or Cool to 10 K
Systems capable of achieving 10
-3
Torr, but unable to achieve and hold between
3 × 10
-4
Torr and 9 × 10
-4
Torr or unable to cool to the specified base temperature, are
the most difficult to troubleshoot, because the symptom can be caused by several
different problems. Contamination in the vacuum chamber and very small leaks are
the most common issues associated with this level of performance.
Suspect contamination if:
D
The system has been left open for extended periods of time
D
The system has been worked on and good vacuum practices were not followed
D
The system has been overheated or operated when not under vacuum
D
The system has been vented to atmosphere while cold
To minimize the effects of contamination:
D
Follow the guidelines in section 6.2.3
D
Follow the guidelines in section 6.2.12
Suspect a very small leak if:
D
The pump passed a blank off test
D
The system is clean and poor vacuum persists
D
Performance degrades the longer the system is cold
D
Sudden changes in vacuum reading are observed when the sample stage is
heated, especially warming above 77 K
The best way to proceed if you suspect a leak:
D
Follow the instructions in section 6.3.1.7 in hopes of sealing the system even if
the exact source is not identified
D
Replace any o-rings that look worn or flattened
D
Clean and re-grease the o-rings between the probe arm base and bellows,
especially if the leak increases when planarization adjustments are made
D
If the pressure relief valve assembly activates routinely, verify that it
reseats properly
Never operate the probe station without a pressure relief valve installed.
If these troubleshooting procedures do not correct the problem, a helium leak
detector will be required to identify the exact source of the leak.
Содержание CRX-6.5K
Страница 4: ...Model CRX 6 5K Probe Station ...
Страница 52: ...42 CHAPTER 2 System Overview Model CRX 6 5K Probe Station ...
Страница 92: ...82 CHAPTER 3 Installation and Setup Model CRX 6 5K Probe Station ...
Страница 162: ...152 CHAPTER 6 Maintenance and Troubleshooting Model CRX 6 5K Probe Station ...
Страница 166: ...156 INDEX Model CRX 6 5K Probe Station ...