Differences Between The Ftla And The Mb3000 Series; Field Of View Effects On Ftir Frequency Scale Calibration; Field Of View Definition - ABB MB3000 Series Installation And User Manual

Appendix E FTIR Frequency scale calibration
Appendix E FTIR Frequency scale calibration

Differences Between the FTLA and the MB3000 Series

Field of view effects on FTIR Frequency scale calibration

The frequency scale of an FTIR is extremely repeatable, reproducible and linear.
The absolute calibration of the frequency scale depends on the frequency assigned
to the reference laser and to a smaller extent on the IR beam angular geometry also
called "field of view".

Field of view definition

The field of view is defined by the shape of the IR beam at the focus of the various
focusing elements of the FTIR system.
The first focus is the source collimator focus where the source is located.
A first conjugate image of the source collimator focus is produced at the output
focusing mirror of the MB3000 interferometer. Its image size is twice the image size
at the source focus: Ratio of source collimator focal length to output focusing mirror
focal length is 1 to 2.
A second conjugate image of the source focus is produced at the sample
compartment IR beam focus. Its image size is 1.4 times the image size at the output
focusing mirror and 2.8 times the image size at the source focus.
Finally there is a third conjugate image of the source focus at the IR detector. Its
image size is 0.167 times the sample compartment image size and 0.467 times the
image size at the source focus. Table 1 summarizes the different field of view
defining positions for the MB3600. The source is a quartz halogen lamp with 1 mm
diameter filament that is ~2.5 mm long. Table 2 summarizes the different field of
AA003700-01 rev. G. 2.0
Differences Between the FTLA and the MB3000 Series
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