PHILIPS SEM 525 INSTRUCTIONS
Start-up:
Turn master mains switch on (if not already on)
Turn the water cooler/circulator timer on to HOLD (counter clockwise)
Press the SEM mains button ON (lower left panel, listen for the mechanical
vacuum pump to come on)
Press the vacuum ON button
The red high vacuum light (left most panel) will be lit. After about 30
minutes, this light indicator will turn off indicating a sufficient vacuum to
operate the microscope. However, to ensure maximum filament life, do not
turn the beam on until the vacuum gauge reads well below “10”.
Turn o n the exposure light column switch.
Turn o n the “marker” switch.
Turn ON the detector and adjust the “Black Level”.
Set the detector to GREY SCALE and adjust brightness and contrast for the
display screens (once set, this does not change appreciably over time).
If using the Polaroid camera, press and hold the photo start button and
press the scan rate 2000 and 32 buttons. This sets the scan rate for the
camera screen. The photo scan can be stopped by pressing the interrupt
b u t t o n .
Adjust operating parameters appropriate to the specimen characteristics.
Select accelerating
voltage:
For maximum resolution and high magnification work, use 25 kV or above
with gun bias setting of “1” and a spot size of 20 or 10. This electron beam
will penetrate well into most samples and require a lower secondary
electron detector gain setting. The detector bias may be turned to negative
to detect backscattered (BS) electrons if desired, but there will be a lot of BS
electrons with this kV setting. A better BS image will be obtained using a
lower accelerating voltage.
