JCAMP-DX (.jdx, .dx) is the plain-text exchange format that spectral libraries, spectrum
databases and most spectroscopy programs import. This page turns a Bruker OPUS file into a
JCAMP-DX 5.01 file without OPUS, for example to add your spectra to a library, share them with a
group that uses different software, or attach them to a publication.
How to convert OPUS to JCAMP-DX
- Upload the OPUS file (
.0,.1…). Several files or a ZIP work too. - Choose the content under Which spectrum. Best available writes the result spectrum (usually absorbance). All data blocks writes every block of the file, including single channels and interferograms, into one linked JCAMP-DX file.
- Optionally convert the axes under More options, for example transmittance to absorbance or wavenumber to wavelength, before the file is written.
- Download the
.jdx.
What the file looks like
- Header: the required labels (title, JCAMP-DX version, data type, units, first and last x,
number of points) and the date as
##LONGDATE. The instrument goes into##SPECTROMETER/DATA SYSTEMand the resolution into##RESOLUTION. Other OPUS parameters, such as beamsplitter, detector, scans or apodization, become##$user labels. - Data: evenly spaced spectra use the uncompressed
##XYDATA=(X++(Y..Y))form with a scaling factor that keeps nine to ten significant digits; unevenly spaced data use##XYPOINTS. Numbers are written in plain form, not compressed with DIF/DUP characters, so simple parsers can read them. - Data type: infrared spectra, Raman spectra and interferograms are labelled as such.
- Several blocks or spectra become one file of
##DATA TYPE=LINKwith a child block per spectrum. - Transmittance in % is written as a fraction between 0 and 1 with
##YUNITS=TRANSMITTANCE, the convention JCAMP-DX uses, and a comment notes the change. - The file is plain ASCII; accented characters in sample names are replaced by their base letters.
How it was checked
Output files were read back with an independent JCAMP-DX reader: point counts matched and values came back within about 1 part in 10 million, for every block type tested. The OPUS reading itself was compared with OPUS's own exports.
When to pick something else
JCAMP-DX suits libraries and spectroscopy software. For Excel, Origin or Python a CSV is simpler: see OPUS to CSV. To look at a file before converting, see opening an OPUS file.
More about what this tool reads and writes: Spectrum File Converter (OPUS, OMNIC, SPC, WDF, SP, JWS).