High accurate peak positions for calibration purposes with the lowest fundamental bands nu(2) of N2O and CO2

The lowest fundamental vibration rotation bands v(2) of nitrous oxide (N2O) and carbon dioxide (CO2) have been measured with a Fourier transform spectrometer at the resolution of 0.001 cm(-1). The spectra have been calibrated with the high accurate peak positions of the carbonyl sulfide (OCS) v(2) band, which has been recently produced as a candidate for a secondary standard by calibrating first the 2v(2) band with the CO2 laser bands around 10 mu m and then transferring the calibration to v(2) with the internal energy levels of OCS. In the present work the OCS v(2) and v, bands were measured together with the spectra of N2O and CO2,. Then the OCS v(1) band was measured by calibrating it with the 2v(2) band of OCS. The linearity of the wavenumber scale was checked by comparing the corresponding line positions in the OCS v, band in these two separate measurements. The absolute accuracy of the v(2) band centers of N2O and CO2 were evaluated to be 6.8 x 10(-6) and 8.4 x 10(-6) cm(-1), respectively. (c) 2006 Elsevier Inc. All rights reserved.