Quartz-Enhanced Photoacoustic Spectroscopy-Conductance Spectroscopy for Gas Mixture Analysis

Abstract

A novel spectroscopic method, named quartz-enhanced photoacoustic spectroscopy-conductance spectroscopy (QEPAS-CS), was first developed for gas mixture analysis. In QEPAS-CS, the advantage of photoacoustic detection and conductance analysis was realized by a quartz tuning fork (QTF). Two-component gas analysis was done by photoacoustic detection and conductance detection. For an explicit application, natural spider silk was used as a water vapor transducer to modify the QTF, making a conductance sensing channel. A 2004 nm laser diode was used as an excitation source for a photoacoustic sensing channel. Such a QEPAS-CS sensor was used for H2O/CO2 gas mixture analysis in a cell incubator. This provides a solution to calibrate an infrared photoacoustic spectroscopy gas sensor. This example effectively confirms the capacity of multigas analysis by the QEPAS-CS sensor.

Pressure-Compensated Fiber-Optic Photoacoustic Sensors for Trace SO2 Analysis in Gas Insulation Equipment

“…The functional relationship between pressure and photoacoustic response should be determined. , The interference analysis of CO 2 on C 2 H 4 at low-pressure of 200 Torr is completed by using quartz enhanced photoacoustic spectroscopy technology − and a 10.5 μm QCL . Apart from spectral interference, the frequency response and cell constant are also the main factors affected by pressure.…”

All-optical non-resonant photoacoustic spectroscopy for multicomponent gas detection based on aseismic photoacoustic cell

“…It plays an important role in trace gas detection. Various kinds of photoacoustic spectral gas detection structures have been reported such as T-type cell [11] , [12] , H-type resonant PAS [13] , [14] , [15] , two channel differential resonant PAS [16] , [17] , [18] and the quartz-enhanced photoacoustic spectroscopy (QEPAS) [19] , [20] . The resonant structure has higher detection sensitivity via resonant amplifying.…”

“…However, the photoacoustic signal could be unstable while the resonant frequency drift in complex application environments. As for QEPAS, the long-term instability also exist while working at the resonant frequency of 32.7 kHz [20] , [21] . Although beat frequency QEPAS can effectively suppress the impact of sensitivity drift near the resonant frequency, the experimental system is complicated [22] .…”

Dense Multibutterfly Spots-Enhanced Miniaturized Optical Fiber Photoacoustic Gas Sensor

“…PAS technology is based on the photoacoustic effect, which converts absorbed photon energy into the translational energy of gas molecules, generating an acoustic wave. − A photoacoustic gas detection system does not require photodetectors, which makes up for the problem of insufficient spectral response bandwidth in TDLAS. In addition, a small volume of photoacoustic cells (PACs) will promote the improvement of the photoacoustic response.…”