Quartz-enhanced photoacoustic sensor for ethylene detection implementing optimized custom tuning fork-based spectrophone

Giglio, Marilena; Elefante, Arianna; Patimisco, Pietro; Sampaolo, Angelo; Sgobba, Fabrizio; Rossmadl, Hubert; Mackowiak, Verena; Wu, Hongpeng; Tittel, Frank K.; Dong, Lei; Spagnolo, Vincenzo

doi:10.1364/oe.27.004271

Cited by 51 publications

(25 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The optical power at the QTF was 25 mW. The QTF was a custom design for QEPAS with a resonance frequency of 12.46 kHz and a prong spacing of 0.8 mm (see [12], design T08, and [13], design S 2 ). The tuning fork including electronic trans-impedance amplification and excitation circuitry was provided as a prototype of a now commercially available QEPAS module (Thorlabs ADM01, Dachau, Germany, compare Figure 1).…”

Section: Measurement Of Humidity Dependent 2f-wm-qepas Signals Of Comentioning

confidence: 99%

Anomalous Humidity Dependence in Photoacoustic Spectroscopy of CO Explained by Kinetic Cooling

2020

View full text Add to dashboard Cite

Water affects the amplitude of photoacoustic signals from many gas phase molecules. In quartz-enhanced photoacoustic (QEPAS) measurements of CO excited at the fundamental vibrational resonance of CO, the photoacoustic signal decreases with increasing humidity, reaches a pronounced minimum at ~0.19%V, and increases with humidity for higher water contents. This peculiar trend is explained by competing endothermal and exothermal pathways of the vibrational relaxation of CO in N2 and H2O. Near-resonant vibrational–vibrational transfer from CO to N2, whose vibrational frequency is 188 cm−1 higher than in CO, consumes thermal energy, yielding a kinetic cooling effect. In contrast, vibrational relaxation via H2O is fast and exothermal, and hence counteracts kinetic cooling, explaining the observed trend. A detailed kinetic model for collisional relaxation of CO in N2 and H2O is presented. Simulations using rate constants obtained from literature were performed and compared to humidity dependent QEPAS experiments at varying pressure. Agreement between the experiments and simulations confirmed the validity of the model. The kinetic model can be used to identify optimized experimental conditions for sensing CO and can be readily adapted to include further collision partners.

show abstract

Section: Measurement Of Humidity Dependent 2f-wm-qepas Signals Of Comentioning

confidence: 99%

Anomalous Humidity Dependence in Photoacoustic Spectroscopy of CO Explained by Kinetic Cooling

2020

View full text Add to dashboard Cite

show abstract

“…Indeed, the light blocked by prongs can result in undesirable background noise which can limit the ultimate detection sensitivity of the sensor [14]. To overcome these limitations, custom QTFs with low-resonance frequencies of a few kHz and prong spacings >700 µm have been proposed for QEPAS [8,14,15,16,17]. The photoacoustic signal S of QEPAS can be expressed as:S=KPLQ(P)α(P)ε(P,f0) where P L , Q , and α , are the laser power, the Q factor of the QTF resonance and the gas absorption coefficient, respectively.…”

Section: Introductionmentioning

confidence: 99%

Influence of Tuning Fork Resonance Properties on Quartz-Enhanced Photoacoustic Spectroscopy Performance

Zheng

Lin

Liu

et al. 2019

Sensors

Self Cite

View full text Add to dashboard Cite

A detailed investigation of the influence of quartz tuning forks (QTFs) resonance properties on the performance of quartz-enhanced photoacoustic spectroscopy (QEPAS) exploiting QTFs as acousto-electric transducers is reported. The performance of two commercial QTFs with the same resonance frequency (32.7 KHz) but different geometries and two custom QTFs with lower resonance frequencies (2.9 KHz and 7.2 KHz) were compared and discussed. The results demonstrated that the fundamental resonance frequency as well as the quality factor and the electrical resistance were strongly inter-dependent on the QTF prongs geometry. Even if the resonance frequency was reduced, the quality factor must be kept as high as possible and the electrical resistance as low as possible in order to guarantee high QEPAS performance.

show abstract

“…Extremely robust and reliable QEPAS sensors implementing standard QTF-based acoustic detection modules (ADM) were demonstrated in literature [23,24] and tested in real world applications [25], and also exploiting the single-mode beam delivery provided by optical fibers in the mid-IR [26,27]. Targeted applications were leak detection [28], hydrocarbon detection [29], and environmental monitoring [30,31].Starting from 2013, several studies have been performed to design QTFs with custom geometries optimized for QEPAS sensing [20,21,[32][33][34][35][36][37][38][39][40][41]]. An extensive investigation correlated the resonance frequency and the quality factor of the fundamental mode of the QTF with the prong sizes and geometry.…”

mentioning

confidence: 99%

“…An extensive investigation correlated the resonance frequency and the quality factor of the fundamental mode of the QTF with the prong sizes and geometry. It has been shown that if some additional mass is added to the free end of the prong, an increase of the global stress field is obtained, enhancing the stress distribution along the internal prong surface and the QTF sound-to-current transduction efficiency [32,33]. In addition, an enlargement of the prongs spacing of up to 1.5 mm can facilitate the optical alignment and minimize the photothermal noise level, allowing the use of laser beams characterized by a non-optimum spatial intensity distribution, such as high-power laser beams [34], THz quantum cascade lasers (QCLs) [35], arrays of QCLs [36,37] and dual-antinode configurations [38,39].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Quartz-Enhanced Photoacoustic Detection of Ethane in the Near-IR Exploiting a Highly Performant Spectrophone

et al. 2020

Self Cite

View full text Add to dashboard Cite

In this paper the performances of two spectrophones for quartz-enhanced photoacoustic spectroscopy (QEPAS)-based ethane gas sensing were tested and compared. Each spectrophone contains a quartz tuning fork (QTF) acoustically coupled with a pair of micro-resonator tubes and having a fundamental mode resonance frequency of 32.7 kHz (standard QTF) and 12.4 kHz (custom QTF), respectively. The spectrophones were implemented into a QEPAS acoustic detection module (ADM) together with a preamplifier having a gain bandwidth optimized for the respective QTF resonance frequency. Each ADM was tested for ethane QEPAS sensing, employing a custom pigtailed laser diode emitting at ~1684 nm as the exciting light source. By flowing 1% ethane at atmospheric pressure, a signal-to-noise ratio of 453.2 was measured by implementing the 12.4 kHz QTF-based ADM, ~3.3 times greater than the value obtained using a standard QTF. The minimum ethane concentration detectable using a 100 ms lock-in integration time achieving the 12.4 kHz custom QTF was 22 ppm.

show abstract

Quartz-enhanced photoacoustic sensor for ethylene detection implementing optimized custom tuning fork-based spectrophone

Cited by 51 publications

References 31 publications

Anomalous Humidity Dependence in Photoacoustic Spectroscopy of CO Explained by Kinetic Cooling

Anomalous Humidity Dependence in Photoacoustic Spectroscopy of CO Explained by Kinetic Cooling

Influence of Tuning Fork Resonance Properties on Quartz-Enhanced Photoacoustic Spectroscopy Performance

Quartz-Enhanced Photoacoustic Detection of Ethane in the Near-IR Exploiting a Highly Performant Spectrophone

Contact Info

Product

Resources

About