Acoustic Detection Module Design of a Quartz-Enhanced Photoacoustic Sensor.

Tingting Wei,Frank Tittel,Hongpeng Wu,Lei Dong

doi:10.3390/s19051093

Tingting Wei, Frank Tittel + Show 2 more

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https://doi.org/10.3390/s19051093

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Journal: Sensors (Basel, Switzerland)	Publication Date: Mar 4, 2019
Citations: 10	License type: CC BY 4.0

Affiliation: Shanxi University, Rice University

Abstract

This review aims to discuss the latest advancements of an acoustic detection module (ADM) based on quartz-enhanced photoacoustic spectroscopy (QEPAS). Starting from guidelines for the design of an ADM, the ADM design philosophy is described. This is followed by a review of the earliest standard quartz tuning fork (QTF)-based ADM for laboratory applications. Subsequently, the design of industrial fiber-coupled and free-space ADMs based on a standard QTF for near-infrared and mid-infrared laser sources respectively are described. Furthermore, an overview of the latest development of a QEPAS ADM employing a custom QTF is reported. Numerous application examples of four QEPAS ADMs are described in order to demonstrate their reliability and robustness.

Highlights

The detection and quantification of trace gas has played an important role in the development and improvement of gas sensing technology
The core component of a Quartz enhanced photoacoustic spectroscopy (QEPAS) sensor is an acoustic detection module (ADM) which determines the performance of the QEPAS sensor
The size of an ADM depends on the dimension of the used spectrophone, which is determined by the used quartz tuning fork (QTF)

Summary

Introduction

The detection and quantification of trace gas has played an important role in the development and improvement of gas sensing technology. Quartz enhanced photoacoustic spectroscopy (QEPAS), since it was first reported in 2002, has become one of the promising optical detection techniques due to the fact that it offers high detection sensitivity with a compact and cost-effective acoustic detection module (ADM) [1,2]. QEPAS is a variant of photoacoustic spectroscopy (PAS) [3,4], in which a quartz tuning fork (QTF) is employed instead of a microphone as a resonant acoustic transducer to detect photoacoustic signals. The QEPAS technique is compared with the other optical detection techniques in terms of sensitivity, complexity and robustness, as shown in Figure 1 [9]. Compared to the conventional optical detection techniques, such as direct absorption spectroscopy (DAS) and wavelength modulation absorption spectroscopy (WMAS), the QEPAS technique has a better detection sensitivity

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