FEI Quanta FEG 250, User'S Operation Manual

Page: 61 / 228

Software Control: xT microscope Control Software
4-33
The ESEM Tab
enables to customize the specimen chamber purging, which is
automatically initiated when the system pumps the vented chamber
directly to the ESEM / Low Vacuum mode.
FIGURE 4-19 ESEM PREFERENCES
Purge Mode module radio buttons:
• No Purge – The purging is switched off and the chamber pressure
goes directly to the set ESEM / Low Vacuum mode value. The gas
mixture in the chamber slowly changes to the new gas type.
• Automatic – All purging parameters are set automatically,
according to the mounted Low Vacuum detector (Cone).
• Custom – The Custom parameters ( Minimum Pressure,
Maximum Pressure , Number of cycles ) defined in the Purge
Settings module edit boxes are used. The default values are the
same as in Automatic mode.
The Purge button enables to start the purging (using the actual Purge
Mode and Settings) manually when the system is already pumped to
ESEM / Low Vacuum; otherwise, the button is disabled. When the
purging is running, the Purge button becomes highlighted. Clicking on
the highlighted button stops the actual purging procedure and returns
the system to operation in ESEM / Low Vacuum.
Notes:
– The new Purge Mode or Settings is applied immediately after pressing
the
OK or Apply button, even if the purging cycle is already running.
– During the purging procedure, the chamber pressure is not ready for
SEM operation (the vacuum status is Pumping). Therefore, pressing
the Purge button automatically switches off the accelerating voltage.
– The Purge Settings is not remembered separately for each user. If it
is of any importance, please check these Preferences before starting
the ESEM / Low Vacuum operation.