Use of Omnic IR data software

Open the Omnic program, if it is not already open. You will get a window that looks like this.
Load the CH 362 Experiment from "Experimental Setup." With no sample in the chamber, click on "Collect" then "Collect Background."
You will get a "spectrum" that looks like this. It represents the energy output of the source. Note the multiple peaks for water vapor at 3500 and 1600 cm^-1. Carbon dioxide appears at 2400 cm^-1.
Mount the sample, and collect the sample spectrum. The data are refreshed every 4 scans, so be sure to complete the data collection! The Fourier transform and subtraction of the background are handled automatically. If for some reason the peaks point up, you may be in absorbance mode (check the Y axis). If so, go to "Process" and choose "% Transmittance." Save the spectrum in your folder on Bitbucket. Use a logical 8-character file name; the three-letter extension .spa must be used. If I had a spectrum that was the first sample described on page 47 of my notebook, I would call it KG47_1.spa.
If necessary you can modify the baseline at this point ("Process," "Baseline Correct"), or enter the "Spectral Math" routine (in the Hacac experiment). Otherwise, select "Analyze" and "Find Peaks." You get a new window with a horizontal line. This cutoff may be moved up or down with the mouse to select more or fewer peaks. Place it where you wish and hit "Replace" (upper right) to get back to the main screen.
You probably want a hard copy printout; this can be generated directly from "File" and "Print" but no file data will be listed. It is better to construct a "Report" using one of the templates. This has the advantage of giving you peak listing.

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Last updated: 01/24/2009