title: Modulation cancellation method for measurements of small temperature differences in a gas.
abstract: An innovative spectroscopic technique based on balancing and cancellation of modulated signals induced by two excitation sources is reported. For its practical implementation, we used quartz-enhanced photoacoustic spectroscopy as an absorption-sensing technique and applied the new approach to measure small temperature differences between two gas samples. The achieved sensitivity was 30 mK in 17 s. A theoretical sensitivity analysis is presented, and the applicability of this method to isotopic measurements is discussed.
authors.affiliation: Department of Electrical and Computer Engineering, Rice University, Houston, Texas, USA. spagnolo@fisica.uniba.it
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Spagnolo
authors.forename: Lei
authors.initials: L
authors.lastname: Dong
authors.forename: Anatoliy A
authors.initials: AA
authors.lastname: Kosterev
authors.forename: David
authors.initials: D
authors.lastname: Thomazy
authors.forename: James H
authors.initials: JH
authors.lastname: Doty
authors.forename: Frank K
authors.initials: FK
authors.lastname: Tittel