If you want an OMNIC spectrum in Excel for a report, a lab notebook or a quick comparison, a CSV
still needs importing, a chart and axis settings. This page writes a ready Excel workbook
(.xlsx) straight from Thermo OMNIC .spa and .spg files, with the chart already in place.
How to convert SPA to Excel
- Upload the
.spafile, an.spggroup, or several files at once. - Optionally change the units under More options: transmittance to absorbance, or wavenumber to wavelength in nm or µm. The workbook is written in the units you choose.
- Download the
.xlsxand open it in Excel or LibreOffice Calc.
What the workbook contains
Data sheet. The x values in the first column, each spectrum in its own column headed with its OMNIC title, and a native Excel scatter chart beside the table. For infrared data the wavenumber axis runs from high to low, the way IR spectra are normally drawn. Groups show up to twelve spectra in the chart; the table has all of them.
Metadata sheet. What the file records about the measurement, including title, collection date and time, y and x units, sample and background scans, resolution, collection time, laser frequency, spectral range and number of points: handy for documenting how a spectrum was measured.
Because an .xlsx stores real numbers, the decimal separator follows your Excel settings
automatically. There is no decimal comma problem as there can be with CSV.
Working with the chart
The chart is an ordinary Excel chart, so you can restyle it, change the axis range to zoom into a region such as the fingerprint region, or copy it into Word or PowerPoint. When you add columns, for example a difference spectrum calculated with a formula, add them to the chart with Select Data.
Tips for OMNIC groups and batches
- An
.spgbecomes one workbook with all spectra side by side, which makes overlays and averages quick. - Uploading several
.spafiles produces a combined workbook as well. Spectra with different ranges get their own x columns. - Very large sets (over six million cells) skip the workbook and keep the CSV, with a note in the result.
OMNIC series files (.srs) aren't supported yet; export the spectra you need as .spa or
.spg first. For a plain text table instead, see OMNIC SPA to CSV.
More about what this tool reads and writes: Spectrum File Converter (OPUS, OMNIC, SPC, WDF, SP, JWS).