Zeiss EVO, Instruction Manual

Page: 26 / 180

3 Product and Functional Description | 3.1 Vacuum System ZEISS
3.1.1.2 Extended Pressure Mode
Purpose Extended Pressure (EP) mode is required for imaging hydrated specimens. This will enable the
study of hydrated specimens in their native state with little or no loss of water in the microscope
(the specimen is kept fully hydrated during the pump down). This pressure mode is typically used
with a Peltier coolstage.
1
1
2
3
4
5
Fig. 9: Extended pressure mode, high vacuum, extended pressure
1 Pre-vacuum pump directly pumping the
chamber 2 Gun at high vacuum
3 Chamber at extended pressure 4 Two pressure-limiting apertures
mounted under the objective lens:
100 μm EP aperture
Either 500 μm or 1000 μm beamsleeve
aperture
5 Isolation valve closed
When the microscope is configured for EP mode, the 750 μm mid-column aperture is used and
the 100 μm EP aperture is mounted under the objective lens in combination with one of the
beamsleeves apertures (500 μm or 1000 μm).
For achievable pressure ranges, refer to Variable Pressure Modes [
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26 Instruction Manual ZEISS EVO | en-US | Rev. 10 | 354706-0780-006