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ZEISS
5 Commissioning and First Operating Steps | 5.7 Working with Variable Pressure
Info
The CL signal is usually very weak and the resolution of the CL image is much worse than an
SE image.
4
Use the SE detector to navigate and focus before acquiring CL images.
The following settings are recommended for the CL detector:
5 kV – 30 kV
6–10 mm
(min. 4 mm)
Procedure
1. In the SEM Controls panel, select the Detectors tab.
2. From the
Signal A
drop-down list, select
CL
.
3. Adjust the EHT and the working distance (WD) according to the suggestions in the table in
order to optimize the image.
5.7 Working with Variable Pressure
VP mode offers the possibility of analyzing and mapping non-conducting, strongly gassing or
moist specimens without any need for specimen preparation.
Info
In VP mode, the InLens SE detector, the InLensDuo detector, and the SE detector cannot be
used.
Mode
Booster
Chamber Pressure
High Vacuum HV
On
< 10⁻² Pa
Variable Pressure VP
Off
2–133 Pa
5.7.1 Changing to Standard VP Mode
Info
If the VP system has not been used for several days, start with moderate pressure up to 30 Pa
for the first 10 minutes.
Afterwards the vacuum system is conditioned and the VP mode can be used with its full range.
Info
A higher pressure can be set within a few seconds. Achieving a lower pressure may require
some more time, because the specimen chamber has to be evacuated by the pre-vacuum
pump.
Prerequisite
ü
The microscope is operating in HV vacuum mode
Procedure
1. In the SEM Controls panel, select the Vacuum tab.
2. In the
Variable Pressure
section, click
VP
.
à
The system sets the chamber pressure to the value displayed in the
VP Target
field. If
you have not changed it, it is the value of the last VP session.
Instruction Manual ZEISS SIGMA series | en-US | Rev. 7 | 352102-9344-006
109