50 . Spotlight 150 User's Guide
Common Window Materials
Both liquid and solid samples are often mounted on salt windows. Very thin windows,
1 to 2 mm thick, give the best spectra. The following materials are commonly used in
windows:
•
KBr: Potassium bromide is inexpensive, and it transmits infrared radiation to below
400 cm
−1
. The major disadvantage of this material is that it is hygroscopic, so that the
windows fog easily.
•
BaF
2
: Barium fluoride is not hygroscopic. Its transmittance cut-off is 750 cm
−1
. It can
break or crack easily.
•
NaCl: Sodium chloride transmits infrared down to 600 cm
−1
. Otherwise, its properties
are similar to KBr.
•
ZnSe: Zinc selenide is not hygroscopic. Its transmittance cut-off is 650 cm
−1
. ZnSe is
more durable than the other windows but is yellow, so that the live image on the Setup
Instrument Microscope tab appears yellow.
Summary of Contents for Spotlight 150
Page 1: ...Spotlight 150 User s Guide MOLECULAR SPECTROSCOPY ...
Page 5: ...Introduction ...
Page 11: ...Warnings and Safety Information ...
Page 23: ...Overview of the Spotlight 150 ...
Page 32: ...32 Spotlight 150 User s Guide ...
Page 33: ...Getting Ready to Use the Spotlight 150 ...
Page 45: ...Preparing Samples ...
Page 58: ...58 Spotlight 150 User s Guide ...
Page 59: ...Techniques for Collecting Spectra ...
Page 94: ...Maintenance ...
Page 102: ...Appendices ...