Abstract
Detection of chlorodifluoromethane (R-22) with unresolved rotational–vibrational absorption lines was demonstrated using quartz-enhanced photoacoustic spectroscopy (QEPAS) and an external cavity quantum cascade laser (EC-QCL). A spectral region spanning 1230–1420 cm−1 was measured. A mini quartz tuning fork with high resonance frequency of ~ 75 kHz is first used to improve the QEPAS sensitivity. At a laser optical power of 2 mW, a 1σ-normalized noise-equivalent absorption of 1.9 × 10−8 cm−1 W Hz−1/2 was achieved. The analysis of a mixture of two broadband absorbers (R-22 and acetone) with overlapping absorption spectra was demonstrated. The good linearity response of the measured QEPAS signal amplitude as a function of R-22 concentration indicates the QEPAS-based sensor has a great potential for continuous and noninvasive real-time monitoring of broadband absorbers.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
