Comparison of cavity enhanced optical–feedback laser spectroscopy and gas chromatography for ground-based and airborne measurements of atmospheric CO concentration
Other literature type
Yver Kwok, Camille
(issn: 1867-8548, eissn: 1867-8548)
We present the ﬁrst comparison of carbon monoxide (CO) measurements performed with a portable laser spectrometer that exploits the Optical–Feedback Cavity–Enhanced Absorption Spectroscopy (OF-CEAS) technique, against a high performance automated gas chromatograph (GC) with mercuric oxide reduction gas detector. First, measurements of atmospheric CO mole fraction were continuously collected in Paris (France) suburb over one week. Both instruments showed an excellent agreement within typically 2 ppb (part per billion in volume) fulﬁlling the World Meteorological Organization (WMO) recommendation for CO inter-laboratory comparison. The compact size and robustness of the OF-CEAS instrument allowed its operation aboard
a small aircraft employed for routine tropospheric air analysis over the French Orléans forest area. Direct OF-CEAS real–time CO measurements in tropospheric air were then compared with later analysis of ﬂask samples by the gas chromatograph. Again, a very good agreement was observed. This work establishes that the OF-CEAS laser spectrometer can run unattended at a very high level of sensitivity (< 1 ppb) and stability without any periodic calibration.