PerkinElmer Spotlight 200, User Manual

Page: 101 / 132

Techniques for Collecting Spectra . 101
NOTE:
When using the automated ATR objective, the background spectrum is always
collected in air at the current stage position, regardless of the
Background Location
settings in the Setup Microscope Data Collection tab.
Before you collect the sample spectrum, you should monitor the spectrum to make sure that
there is good contact between the crystal and the sample at the chosen stage position.
7. Click on the Measurement toolbar.
The software asks if you want the ATR crystal to make contact with the sample
automatically.
8. Click Yes .
The stage moves upwards until the sample just touches the ATR crystal.
OR
Click
No .
The stage remains lowered to allow you to adjust the height manually.
9. On the Monitor dialog, choose Sample .
10. Use the Adjust Up button to move the stage upwards until a spectrum is seen in
the Live tab.
The Sample Force being applied by the crystal is shown under the Stage View pane
both in units and as a percentage of the maximum possible value.
11. Adjust the stage position until a satisfactory spectrum is seen in the Live tab.
NOTE:
You can change the size of each stage Z-axis adjustment step using the options in
the Setup Microscope Basic tab.
12. When the spectrum is satisfactory, click .
The sample spectrum is collected.
Scanning Markers, Lines and Maps
If your sample contains many features that you want to scan, it is more efficient to add
markers, lines or maps in the Stage View that the system can then analyze automatically.
You can either add markers manually or use the Analyze Image options which detects
regions of interest and then places a marker in each region with optimum aperture sizes.
Lines and maps, which are collections of markers, can also be added, but the apertures for
these markers need to be set manually. Refer to the on-screen Help for more information on
setting up markers, lines and maps, and using the Analyze Image processes.
With an automated ATR objective, you can set the stage position for scanning using either
stage height or applied pressure. If your sample has an uneven surface, then it is safer to
use the pressure option to set the height of the sample stage and make sure that there is
firm contact between the ATR crystal and the sample for all measurements. For a flat
sample, you can choose to use the same stage height for all markers, which will reduce the
time needed to collect the spectra.