5 OPERATION
5-8
EM210F-1
4.
Open the nitrogen gas source valve.
5.
Remove the holder from the goniometer.
a.
Pull the specimen holder until it stops.
b.
Turn it fully counterclockwise.
c.
Pull it until it stops
d.
Turn it fully counterclockwise.
e.
Set the PUMP/AIR switch on the goniomter and wait 30 seconds.
f.
Remove the holder from the goniomter.
Push in completely.
Turn completely.
Holder insertion
Turn completely.
Set the switch
to PUMP.
Align guide pin and push in.
Turn completely.
Holder removal
Pull out completely.
Set the switch
to AIR.
Wait for 30 seconds and
remove the holder.
Pull out until the holder stops
and turn it completely.
Fig. 5.9 Specimen holder handling
5.2.4 Electron Beam Generation
The “High Voltage Control” screen is used to generate electron beam generation. The
generation condition in the automatic mode can be changed on the screen. The new
condition is saved and used when generating an electron beam next time.
The following items should be kept in mind while the electron beam is being generated.
The electron gun filament may be damaged if these items are ignored.
·
The isolation valve (V1) should be closed before carrying out specimen holder
insertion/removal.
·
The valve (V1) should be closed after shutting down the instrument.
·
The accelerating voltage should not be turned off.
·
The conditioning knob should not be moved.
5.2.4a
Outline of beam generation
The following is a flowchart of the routine operation assuming that the instrument is used
at 200 kV. The HT conditioning is required before generating an electron beam. The
period of the time required for generating/stopping the beam is as follows:
HT conditioning:
About 50 minutes.
Beam generation:
1 hour and half to 2 hours
HT increment to 200 kV:
About 3 minutes
Stopping beam generation:
About 1 minute
