7.1.3 Adjusting grid ion source
Procedure
1. Start with the last values that provided good results, the values from the test log or, if nothing bet-
ter is available, with typical values.
2. Adjust the "
IonRef
" to maximum peak height, however the value always has to be higher than the
"
Cathode
" value, else electrons can get onto earthed parts and desorb the ions there.
3. Increase the "
Field Axis
" value until the peak tips "fray" and reduce it again, until a clean peak
shape is achieved.
4. With "
Resolution
", set the desired resolution, ideally unit resolution ΔM
10
= 1.
5. If necessary, repeat steps 3 and 4.
6. Determine the best HF cable polarity.
7.2 Operating analyzer at high temperature
Procedure
► The analyzer can be heated to a maximum of 180 °C during operation.
► The EP 422, CP 400 and HF generator can be heated to max. 50 °C.
7.3 Removing/installing connector plates
Remove the connector plates for bakeout temperatures >200 °C.
Required tools
● Allen key,
WAF 1.5
1
Fig. 18:
Connector plates
1 Screening sleeves
Removing connector plates
1. On the 90° version, remove the SEM connector plate, but leave the three studs in place.
2. Remove the protective pipe of the large connector plate.
3. Loosen the hexagon socket screw (1.5 mm WAF) of the screening sleeve by ½ a turn.
4. Push the screening sleeves up to the connector plate and fasten them there.
5. Unfasten the hexagon socket screws (1.5 mm WAF) on all plugs.
6. Unfasten the yellow/green ground conductor.
7. Carefully remove the connector plate.
8. Do
not
remove the guard ring and studs.
Installing connector plates
1. Check that the three studs are securely fastened.
2. Carefully position the connector plates so that the plugs fit onto the associated feedthroughs.
3. Fasten the yellow/green ground conductor.
4. Fasten the connector plates with three screws and lock washers.
5. On all plugs, slightly tighten the hexagon socket screws (1.5 mm WAF), but take care not to apply
force to the feedthroughs.
Operation
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