Download CM20 USER GUIDE

CORRECTING OBJECTIVE ASTIGMATISM
METHOD A: TV camera
● Find some amorphous material on your TEM sample
– e.g. amorphous
h
carbon
b supportt fil
film, glue
l liline ffor sandwich
d i h cross-section,
ti
or amorphised layer on edge of crystal left from ion bombardment.
● FOCUS the amorphous material, and increase
MAGNIFICATION to e.g. 135000x.
● Move stage so that amorphous material is in the centre of the
screen. If you are using the C-Au standard alignment sample,
make sure you are seeing at least one gold particle.
● Focus so that you are close to absolute focus (i.e.
minimum contrast). Centre beam with beam SHIFT
X and
d Y.
Y Adjust
Adj t INTENSITY to
t so that
th t the
th beam
b
is
i
spread over most of the fluorescent screen.
● On CCD camera control box to left of
microscope column, make sure CAMERA is
switched to OUT.
● Turn on the TV camera power with the switch
on the power supply box to the left of the door
door.
(Green LEDs come on.)
● Turn on the VHS recorder by pressing the
OPERATE button on the left of the unit.
(Red LED comes on.)
21