PerkinElmer Spotlight 400 Series, User Manual

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Techniques for Collecting IR Images and Spectra . 83
5. Retract the crystal using the toggle bar.
When the crystal is retracted, the tape returns to its previous shape. The impression
disappears after a few seconds so you must perform the next three steps quickly.
To increase the life of the impression, raise the sample stage slightly using the arrow
buttons in the Focus section of the Control dialog.
6. Focus the visible illumination on the tape.
7. In the Monitor Visible window look at the impression of the crystal on the tape. Decide
whether the impression is in the center of the field of view.
If the impression is in the center of the field of view, the assembly is aligned.
If the impression is not in the center of the field of view:
1. Loosen the two knurled thumb-nuts under the ATR crystal holder half a turn.
Figure 33 Centering the ATR crystal
2. Move the ATR crystal holder using the adjusting levers until it is centered.
One lever moves the assembly backwards and forwards and the other from side to side.
3. Tighten the knurled thumb-nuts.
4. Move the microscope slide to a fresh area of tape.
5. Lower the crystal onto the tape.
6. Retract the crystal using the toggle bar.
7. Look through the imager at the impression of the crystal on the tape, and decide
whether the impression is in the center of the field of view.
8. If necessary, repeat steps 1 to 7 until the ATR objective is aligned.