Figure 5-3. Unstable Flow Or Insufficient Output Exists Troubleshooting Flow Chart - Advanced Energy FC-77 Series User Manual

Check for stable pressure
on both the inlet and outlet
sides of the MFC.
Check that the pressure
differential between the
inlet and outlet sides of the
MFC is correct.
Check whether MFC is
being used with specified
Check for interference with
the pressure regulator.
Check for interference
between the pressure
regulator and other MFCs.
Check whether a
temperature gradient may
be causing vapor
condensation in the piping.
Perform an overall leak
check on the system and
Figure 5-3. Unstable Flow or Insufficient Output Exists troubleshooting flow
5700512-C
Series FC-77X / 77XX, Series FC-78X / 78XX, and Series FC-79X MFCs
Not OK
OK
Not OK
OK
Not OK
gas.
OK
Not OK
OK
Not OK
OK
Not OK
OK
Not OK
MFC.
chart
Troubleshooting and Global Customer Support
Ensure that pressure is stable on
inlet and outlet sides.
Adjust pressure to meet pressure
differential specifications. See the
"Specifications" section in
Chapter 6.
Using a gas other than the one
specified for the MFC may cause
hunting. Reducing the pressure
differential across the MFC may
eliminate this problem.
Check the operation timing and
piping design. Also check the
constants used with the pressure
regulator.
Check the operation timing and
piping for all related MFCs.
Vapor condensation may cause
output fluctuations. To prevent
condensation, check the
temperature control on the piping
and/or shorten the piping.
Leaks from the piping may cause
output fluctuation. See the "Leak
Check" section in Chapter 3.
5-5