ROUTINE WAVE-NUMBER CALIBRATION OF AN FT-RAMAN SPECTROMETER

A readily automated procedure for testing and calibrating the wavenumber shift scale of an FT-Raman spectrometer is described. The procedure uses atomic lines as wavenumber standards. An apodization procedure is used in accurately determining the line positions to a fraction of the sampling interval. A fiber-optic bundle conveniently couples the output from a hollow cathode lamp to the collection optics of the Raman accessory. Results are reported and compared for both thorium and neon atomic lines. Acetonitrile is suggested as a wavenumber shift standard, and peak shifts have been measured for its major features. Peak shift values are reported for 11 lines of cyclohexane.