PerkinElmer Spotlight 200, User Manual

Page: 38 / 132

38 . Spotlight 200 User’s Guide
IR optics in reflectance
IR optics in reflectance differs from viewing in reflectance as follows (Figure 13):
• The toroid moves to send the beam to the Reflectance illuminator assembly dichroic
mirror, which sends it through the upper cassegrain.
• The beam is reflected off the sample and back through the other side of the cassegrain,
toward the remote aperture.
•
The detector cassegrain focuses the beam on to the detector.
Figure 13 Path of the Infrared Beam for Collecting IR Spectra in Reflectance
NOTE:
Figure 13, above, illustrates a Spotlight 200 with an MCT detector. Other detector
types may look different, but the optical arrangement is the same in all cases.
Dichroic mirror
Variable aperture
Reflectance
illuminator
assembly
Upper
cassegrain
Sample position
Lower cassegrain
Detector cassegrain
Detector
Source toroid