Operating Procedures: Microscope Control
5-6
User Manual
C O N F I D E N T I A L –
limited rights
Feb 2018
Revision A
Microscope Control
It is assumed that the microscope is in its Full operation state (see Chapter 2).
Operation Pre-Check
To ensure correct operation check the following list before continuing. After obtaining a preliminary image, you can
then experiment with your own settings.
Table 5-1:
Apreo setup conditions
Adjustment Electron
Beam
Setting
Vacuum mode
High Vacuum
: conductive samples
Low Vacuum
: nonconductive, mixed or contaminating samples
Column Use Case
Standard
Accelerating Voltage
Select voltage relative to the specimen type:
- low kV for surface imaging, beam-sensitive samples and slightly charging samples
- high voltage for conductors, high resolution, composite info (BSE, X-ray)
Examples:
- biological samples HV = (1 – 10) kV
- metal samples HV = (1 – 30) kV
Beam Current
Spot size
100 pA at 30 kV
High Vacuum
/
Low Vacuum
: 5 – 6
Scan rate
High Vacuum
: fast scan (dwell time 0.1 - 0.3
µs
)
Low Vacuum
: slow scan (dwell time about 3
µs
)
Working Distance
(FWD)
Set the highest specimen point to approximately 10 mm (yellow mark in an optical
imaging display), tilt to 0° and press Ctrl + F (set FWD to 10 mm function).
Eucentric Position
10 mm
Magnification
Set to lowest, from 20× to 200×
Standard Detector
High Vacuum
: ETD (SE)
Low Vacuum
: LVD
Filtering
High Vacuum
: Average (2-4 frames for fast scans)
Low Vacuum
: Live
Contrast
and Brightness
With contrast at the minimum value, adjust the brightness to just show a change in
intensity on the screen. Increase the contrast to produce reasonable imaging. Increasing
brightness and decreasing contrast produce softer imaging and vice versa.
