Ametek Dycor Dymaxion Mass Spectrometer, User Manual

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6-12 | Dycor Dymaxion Mass Spectrometer
Troubleshooting the Dymaxion
Things to Check First
In many cases, a system failure is not due to a problem with an electronic com-
ponent, but rather to one of the following:
Operation at too high pressure (greater than 1 x 10
-4
Torr).
Improper setting of parameters on a source or calibrate button.
Incorrect or improper cable connection.
Burned out filament.
Shorted-out ion source parts usually resulting from an incorrect fila-
ment or source replacement.
Quick and Easy Solutions
The first step in providing a solution to the problem is performing these checks.
1.
Make sure the quadrupole rod assembly is properly supported within
the vacuum housing.
2.
Check for leaks in the vacuum system.
The system will not work properly (emission current control) if the
vacuum system pressure is higher than 1 x 10
-4
Torr. Power is auto-
matically shut off from the unit above 2.5 x 10
-3
Torr, if used with the
AMETEK sensor manifold.
3. Make sure all cables are connected properly to the Dymaxion unit.
4.
Make sure that the Dymaxion is fully pushed onto the feedthrough
contacts. Reset the Dymaxion by unplugging the power cable from the
unit and plugging it back in.
5.
Check the continuity between the filament feedthroughs.
Although protected, the yttria coated iridium filament will eventually
wear out. The best way to determine if this is the case is to check
the fila-ment continuity.
− The check should be performed on the pins on the atmosphere side of
the unit (Figure 6-7).
− The pins should be electrically isolated from each other and from
ground.
− There should be approximately one ohm continuous circuit between
the filament Pins 3 and 8. They should be isolated from ground.
− If no continuity exists between Pins 3 and 8, remove the quadrupole
head from the vacuum system and replace the filament assembly with
a replacement filament assembly.
If the problem persists after going through these steps, you will have to local-
ize the problem area. These potential problem areas are:
• Dymaxion Communications and LEDs
• Filament Trip/Overpressure and LEDs