Bruker HYPERION, User Manual

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110 HYPERION User Manual Bruker Optik GmbH
Operation 4
4.17 Purging the microscope
Purging the microscope with dry air or nitrogen gas is only of relevance for performing IR
spectroscopic measurements. It is recommended, but not required.
Purging with dry air or nitrogen gas reduces the content of unwanted atmospheric com-
ponents like water vapor and carbon dioxide inside the microscope. Especially the water
vapor in the ambient air absorbs IR radiation. These absorptions are unwanted because
they manifest in the spectrum. In the worst case, H
2
O bands mask the spectral bands
resulting from the sample. Therefore, purging the microscope is recommended, espe-
cially in areas with a high relative air humidity.
Despite purging the microscope, the IR beam is normally exposed to the ambient air in
the area between the objective and the sample. Optionally, you can shield this area for
purging purposes as follows:
• by pulling down the plastic shroud of the 15x objective (See fig. 4.12a.)
• by using the optional purge housing
1
(A684-3) (See fig. 4.12b.)
☞
For information about the purge gas supply requirements, see section 2.5.
☞
For information about how to connect the microscope to the purge gas supply line,
see section 2.8.
1. The purge housing design ensures a reduction of environmental influences on the sample area.
Figure 4.12: a) Standard 15x objective with the plastic
shroud being pulled down
Figure 4.12: b) Microscope with
purge housing