Particulate Systems HPVA Series, Руководство оператора, Страница: 83 / 124

Mar 2011 6-1
6. Troubleshooting and Maintenance
The HPVA system has been designed to provide efficient and continuous service. However, certain
maintenance procedures should be followed to obtain the best results over the longest period of time.
This chapter includes troubleshooting and maintenance procedures.
Troubleshooting
Most operational problems are caused by:
• Leaks (commonly around the sample tube O-ring at the analysis port)
• Sample weighing errors
• Impure gas supply

Always check these first when expected experiment results are not obtained. Some common opera-
tional problems, which are not indicated on the video monitor screen, and their respective causes and
solutions are provided in the following table.
What Happened Why What To Do
Vacuum error, such as
vacuum gauge cannot
reach lower limit Vacuum pump hose leaking
around an O-ring. The vacuum pump hose uses
four O-rings:
• Two on the tee-connector/
hose connection
• One on the hose/instrument
connection on the rear panel
of the instrument
• One on the hose/vacuum
pump connection
These O-rings must be
properly greased and must not
be worn or cracked.
Check the O-rings and grease
or replace as necessary.
Vent valve 2 is open allowing
ambient air to be ingested. Close Vent valve 2, flush with
helium, then vacuum.