Hitachi Microscope & Magnifier S-3400N User Manual
4.1.5
4 - 19
4.1.5 Cleaning of Aperture Plates
(1)
(1)
Use the vacuum evaporator for heating aperture plates. For handling of the vacuum
evaporator, refer to the instruction manual of the evaporator.
evaporator, refer to the instruction manual of the evaporator.
(2)
Mount the molybdenum board in the vacuum evaporator. (See Fig. 4.1-38.)
(3)
Evacuate the vacuum evaporator to better than 5
× 10
-3
Pa.
Heat the molybdenum board. Continue applying heater current until the molybdenum
board becomes incandescent. Do not apply too much heater current, otherwise the
molybdenum board may be melted.
board becomes incandescent. Do not apply too much heater current, otherwise the
molybdenum board may be melted.
(4)
After completion of heating the molybdenum board, wait about 5 minutes for cooling down.
And then introduce air into the vacuum evaporator.
And then introduce air into the vacuum evaporator.
(5)
Mount an aperture plate at the center of the molybdenum board.
(6)
Evacuate the vacuum evaporator to a high vacuum better than 5
× 10
-3
Pa.
Apply heater current. Heat the molybdenum board up to the incandescent point and then
stop heating. Be careful not to heat for a long time.
stop heating. Be careful not to heat for a long time.
(7)
After completion of heating, wait for 10 to 15 minutes and introduce air into the vacuum
evaporator. Then remove the aperture plate with tweezers.
evaporator. Then remove the aperture plate with tweezers.
CAUTION: Do not touch the heated aperture plate directly with bare hands.
Fig 4.1-38 Baking of Aperture Plate
Molybdenum board
(533-1337)
Aperture plate