Stanford Research Systems RGA100, Operating Manual And Programming Reference

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Basic Troubleshooting 9-9
SRS Residual Gas Analyzer
readings at high masses .
Troubleshooting:
x
Is the quadrupole probe connected to the ECU box?
The ECU’’s RF P/S does not operate properly in the absence of a probe.
x
Is the RGA Cover Nipple in place?
The SRS RGA will not operate without the RGA Cover Nipple in place.Consult
Hardware Modifications in the RGA Probe chapter of the manual for details.
x
Are the electronics warmed up?
The RF P/S is optimized at the factory in a completely warmed up ECU box. Cold
operation reduces the efficiency of the RF P/S and can, in some cases, lead to an
RF P/S error. To
completely warm up the RGA electronics (and match the factory
conditions) turn on the filament to the desired emission current and let the
electronics warm up for at least 15 minutes. Once the warm-up time has elapsed,
try to operate the RGA to see if the problem has disappeared (for example, trigger
a scan over a large mass range.) If the problem is still present, warm up the unit
further by performing one or more Degas cycles or setting the quadrupole mass
filter to
t
50 amu for 15 minutes (see Programming the Quadrupole Mass Filter in
Chapter 6 of the manual). It is good practice to keep the filament on as long as the
RGA is turned on. Operating the filament keeps the electronics and the probe
completely warmed up and assures reproducible readings at all times. The
filament is burn-out resistant and will operate continuously for a long time.
Note: During the warm-up period, RGA Windows users should see that the mass
range over which the RGA can be operated reliably increases with time until it
goes beyond the user’’s requested scan range. No more warnings are posted
beyond that point. If no improvement in the mass range is seen as the unit warms
up then go on with the troubleshooting procedure.
x
Is the probe correctly connected to the ECU box?
Try disconnecting and reconnecting the ECU box to the probe. Securely
tighten the thumb screws to make sure good contact is made between the RF
P/S and the quadrupole rod pairs.