PerkinElmer Spotlight 400 Series, User Manual

Page: 88 / 120

88 . Spotlight 400 Series User’s Guide
Collecting Spectra Using the ATR Crystal
Collecting a Background Spectrum
CAUTION
To prevent serious damage to the crystal, do not move the sample stage
while the ATR crystal is in the lower, working position and touching or
near to the sample.
1. Place the slide holding the reference mirror (supplied with the imaging system) on the
microscope slide.
2. Make sure that
Point mode
is selected on the Control dialog.
3. Make sure that the imager is in reflectance mode by choosing
Reflectance
on the
Control dialog.
NOTE: Diffuse reflectance mode can also be used with the ATR crystal. A white reflector is a
suitable background reference material (a slide is supplied with InGaAs systems).
4. Look at the image in the Monitor Visible window and focus on the surface of the mirror
using the Z-control on the joystick.
There are usually dust particles or scratches on the surface that you can use to focus
on.
5. Lower the ATR crystal to the working position.
6. Set the infrared aperture to a suitable size and rotation.
Refer to
Setting the Infrared Aperture
in the on-screen Help.
The contact area of the ATR objective is approximately 100 µm in diameter. We
therefore recommend that you use a maximum aperture size of 100 × 100 µm.
7. Display the Options menu on the Stage Control window, and select
Set Background
Position
.
The background position is set. Do not move the stage before you collect the
background spectrum. If you move the stage, you may cause serious damage to the
ATR crystal.
8. Display the Scan menu in the Stage Control window and select
Background
.
The Scan Background dialog is displayed.
9. Select the Scan Parameters and Display Mode you want.