JASCO's Spectra Manager saves measurements from its FT/IR, UV-Vis (V-series), circular dichroism
(J-series) and fluorescence (FP-series) instruments as .jws files. Only Spectra Manager opens
them, and it usually runs on the instrument PC. This page reads .jws files directly and gives
you CSV, Excel and JCAMP-DX files.
How to convert JWS to CSV
- Upload the
.jwsfile, or several of them. - Look at the preview: the spectrum, the instrument model and the list of channels in the file.
- For files with several channels, choose what goes into the main CSV under Which spectrum: the main signal by default (CD for a CD measurement), or All data blocks for every channel side by side.
- Download the CSV, with the x axis first, for example
Wavelength (nm), and the channel name and unit as the column header.
.jws files come in two different internal layouts; both are read, and so are the .jrs
files that some instruments save themselves.
Multi-channel files, such as CD
A CD measurement records several signals at every point: the CD signal in mdeg, the photomultiplier HT voltage and, on a J-1500, the absorbance. All of them are read:
- the main CSV holds the CD channel (
CD (mdeg)), or every channel with All data blocks; - a ZIP contains each channel as a separate CSV;
- the Excel workbook has the data on the first sheet and one sheet per further channel (HT voltage (V), Absorbance), plus a metadata sheet.
The HT voltage is useful for judging where the CD data become unreliable at short wavelengths,
so it is worth keeping next to the CD trace. Melting curves (CD against temperature) come out
with a Temperature (C) column.
Other JASCO instruments
- FT/IR (for example the FT/IR-4600 or FT/IR-4700 with ATR): the spectrum over wavenumber, as %T or absorbance as recorded.
- UV-Vis (V-series): absorbance, %T, %R or a single-beam channel over wavelength. Time-course measurements give absorbance against time; the file does not record whether the time was set up in seconds or minutes, so the column is labelled seconds with a note.
- Fluorescence (FP-series, for example FP-8300): the emission or excitation spectrum.
Wavelength ↔ wavenumber and transmittance ↔ absorbance conversions are available under More options.
Accuracy
Readings were compared with an independent open-source .jws reader (all channels identical)
and with Spectra Manager text exports of FT/IR, V-730 UV-Vis and J-810 CD measurements, which
match within their printed rounding. Upload the original .jws rather than a text export: it
holds every channel at full precision.
Other spectroscopy formats are listed on the Spectrum File Converter.
More about what this tool reads and writes: Spectrum File Converter (OPUS, OMNIC, SPC, WDF, SP, JWS).