Zeiss EVO - Page 24

3 Product and Functional Description | 3.1 Vacuum System ZEISS
Mode Application
Pressure-lim-
iting aper-
ture
Mid-col-
umn aper-
ture
Filament Min/Max
Pressure in
Pa
EasyVP
mode
Charge com-
pensation
+ Possibility
to switch to
HV mode
400μm
EasyVP
20μm LaB₆ 10–133
EP mode Charge com-
pensation
+ Improved
image qual-
ity
+ High accu-
racy EDS
analysis
100μm EP
+ 500μm
beamsleeve
750μm W, LaB₆ 10–400
Hydrated
specimen
imaging
100μm EP
+ 500μm
beamsleeve
750μm W, LaB₆ 10–3000
Hydrated
specimen
imaging
100μm EP
aperture
+ 1000μm
beamsleeve
750μm W, LaB₆ 10–1000
* If your microscope is a VP type instrument with the through-the-lens pumping option, then
the maximum pressure in VP mode can be increased to 400Pa.
Tab.3: Comparison of Vacuum Modes EVO
For all charge compensation methods, both, air and water vapor can be introduced into the
chamber as a charge compensating gas.
3.1.1.1 Variable Pressure Mode and EasyVP Mode
Purpose
VP mode and EasyVP mode allow partial pressures above 10Pa to be set in the specimen cham-
ber while maintaining high vacuum in the gun area.
2
1
2
3
4
5
Fig.7: Vacuum system in VP or EasyVP mode, high vacuum, variable pressure
24 Instruction Manual ZEISS EVO | en-US | Rev. 10 | 354706-0780-006