Condenser Lens Aperture Replacement - Hitachi TM3030 Plus Instruction Manual

5.3 Condenser Lens Aperture Replacement

The condenser lens aperture is built into the liner tube and it is located underneath the
anode. After the system has been in use for about 6 months and if it appears that there is
image deterioration (an out-of-focus condition), replace the condenser lens aperture. When
replacing the condenser lens aperture, it is recommended that the objective aperture be also
replaced at the same time.
1. Introduce air into the specimen chamber.
Press the EVAC/AIR switch to introduce the air into the specimen chamber. After
completing the introduction, The lighting pattern of AIR LED (yellow) changes from
blinking to lighting.
2. After confirming that AIR LED lights yellow, terminate the application program and turn
off the power switch on the right side of the main unit.
CAUTION: After the system has been in use, the Wehnelt and the anode around the
filament are heated about 90  C. Touching any of them can cause burns.
Before undertaking any filament replacement work, turn off the main unit
and wait at least 30 minutes to allow it to cool down.
3. Wait for a minimum of 30 minutes, and then open the top cover. Holding onto the lower
part of the top cover with your finger tips, gently lift it.
4. Tilt the electron gun to the left side of the system until it touches the cushion.
The anode has a screw-in structure. Put on gloves, and remove the anode by turning it
counterclockwise. Cover the removed anode with clean aluminum foil or place it in a
plastic bag to protect it from particles or scratches.
Cushion
Figure 5.3-1 Opening and Closing the
Electron Gun
Figure 5.3-2 Removing the Anode
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