Stanford Research Systems RGA100, Operating Manual And Programming Reference

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8-8 Ionizer Replacement
SRS Residual Gas Analyzer
Ionizer Replacement
As the RGA is used, deposits form on the ionizer parts and the sensitivity of the sensor is
degraded. Once the sensitivity of the spectrometer is significantly affected by this buildup
it is necessary to completely replace the ionizer. All components of the ionizer should be
replaced together at once. The replacement procedure is simple and should only take a
few minutes.
It is recommended that the filament be replaced as well during this procedure since some
damage to its Thoria coating is inevitable during handling.
Equipment
x
Ionizer Replacement kit (O100RI): consisting of repeller cage, anode grid, focus
plate, and spare screws and e-clips.
x
One standard OFHC copper gasket for 2 3/4”” CF Flange. New and Clean!
x
Precision flat-head screw driver: 2.5 mm head.
x
Needle nose pliers.
x
Latex gloves/powder free.
x
Clean, dust-free work area.
Procedure
1. Read all warnings at the beginning of this chapter before attempting to service the
probe.
2. Set up in advance a clean dust-free working area where to carry out this procedure.
3. Turn off the RGA and disconnect the ECU from the probe.
4. Wait for the probe to cool down for at least 30 minutes after the emission is turned
off. Severe burns can result if the probe is handled too soon .
5. Without disconnecting the RGA Cover Nipple from the vacuum port, remove the six
bolts from the feedthru flange at the end of the probe and slide the entire probe
assembly out of the vacuum system (Note the rotational orientation of the Feedthru
Flange before removing the probe assembly from the vacuum system so that the
probe can be reassembled in the exact same way at the end of the procedure. Mark
the side of the flanges with a permanent marker if necessary.) The ionizer, the filter,
and the detector are now fully exposed and easily accessible.