We present results demonstrating real-time sensing of four different fluorocarbons at low-ppb concentrations using an external cavity quantum cascade laser (ECQCL) operating in a swept-wavelength configuration. The ECQCL was repeatedly swept over its full tuning range at a 20 Hz rate with a scan rate of 3535 cm-1/s, and a detailed characterization of the ECQCL scan stability and repeatability is presented. The sensor was deployed on a mobile automotive platform to provide spatially resolved detection of fluorocarbons in outdoor experiments. Noise-equivalent detection limits of 800-1000 parts-per-trillion (ppt) are demonstrated for 1 s integration times.
Revised: May 20, 2014 |
Published: May 4, 2014
Citation
Phillips M.C., M.S. Taubman, B.E. Bernacki, B.D. Cannon, R.D. Stahl, J.T. Schiffern, and T.L. Myers. 2014.Real-Time Trace Gas Sensing of Fluorocarbons using a Swept-wavelength External Cavity Quantum Cascade Laser.Analyst 139, no. 9:2047-2056.PNNL-SA-98151.doi:10.1039/c3an01642k