ThermoFisher Scientific DXR xi, Руководство пользователя

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3
OMNICxi Software Operation
Acquire and Analyze Data
128 DXRxi User Guide Thermo Scientific
Table 23. Acquisition window, standard settings for acquiring a chemical image
Feature Description
Laser power Laser energy at the sample in milliwatts (0 blocks the laser).
Highest available laser power setting depends on the installed
laser.
Higher power increases the height of spectral peaks. However,
some samples may be burned or damaged when laser power is too
high.
Exposure time Laser exposure time for each collected spectrum in fractions of a
second. Also indicates the speed of acquisition in Hz (i.e., number
of spectra acquired per second).
Longer exposure times may increase the height of spectral peaks
but will also increase scan time.
Number of scans Number of times a region is scanned during data acquisition.
Spectra collected from multiple scans are averaged.
Using a higher number of scans setting may reduce noise in the
spectral baseline due to signal averaging. However, increasing
number of scans also increases the time required to acquire the
data.
Image pixel size Distance the stage moves between sampling points in the chemical
image in micrometers. For example, if Image pixel size is 5 μm,
each spectrum represents 5 μm of sample area averaged together.