Appendix C - Scan/Calibration Procedure; Introduction - Thermo Scientific MIRAN 205B Series Instruction Manual

Appendix C
Scan/Calibration Procedure
Note: Creation of custom calibrations should only be attempted by personnel familiar
with laboratory procedures, especially the preparation of chemical samples. A working
knowledge of infrared spectra is also recommended as the results of the scanning need to
be interpreted to yield the best results. Thermo Fisher Scientific strongly suggests that a
single gas application and validation for proper performance is attempted before
attempting a multi-gas application. Please contact Thermo Fisher Scientific if problems
are experienced.
Requirements: The following requirements are necessary before attempting
calibration:
 Knowledge of correct procedures for handling chemicals
 Knowledge of Microsoft Excel or other suitable spreadsheet program
 Closed Loop Calibration System
 Suitably sized gas and/or liquid syringe(s)

INTRODUCTION

Before calibrating an application, the analyzing wavelength of the compound of interest
must be established. If the wavelength for the compound of interest is known, a scan for
the analyzing wavelength is not necessary. However, a more precise analysis is
accomplished if the calibration is adjusted for the specific instrument. If the wavelength
is unknown, a scan can determine the best analyzing wavelength.
The SapphIRe can do either a peak pick, fast scan, or full scan. A Peak Pick scan should
be used when the approximate wavelength of the compound of interest is known. Peak
Pick provides a 2.0 micron window (user selectable) of the linear variable filter (LVF)
between 8.0 and 14.1 microns to be scanned. All analyzers operating at software version
4.00 or higher possess this feature.
The Fast Scan or Full Scan allows the entire LVF region between 7.7 to 14.1 microns, as
well as the seven fixed band pass filters, to be scanned. This is especially valuable when
the region of strongest absorbance is unknown. It also may be used to record the spectral
characteristics of a gas. The fast scan takes slightly less time while still providing a good
spectral representation of the gas. The full scan take slightly longer, but provides higher
quality spectral identification through better signal to noise averaging.
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