Photoacoustic spectroscopy of CO<sub>2</sub>laser in the detection of gaseous molecules

Lima, Guilherme Rodrigues; Sthel, Marcelo Silva; Silva, M G da; Schramm, D.U.; Castro, Maria Priscila Pessanha de; Vargas, H.

doi:10.1088/1742-6596/274/1/012086

Cited by 4 publications

(4 citation statements)

References 24 publications

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“…This indicates that a measurement system for mobile use is available. Other examples for research on this topic are described in Lima et al [20], Mothe et al [21], Schmitt et al [22] and Nägele et al [23].…”

Section: (A) Photoacoustic Spectroscopymentioning

confidence: 99%

Ethylene detection in fruit supply chains

Janssen

Schmitt

Blanke

et al. 2014

Phil. Trans. R. Soc. A.

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Ethylene is a gaseous ripening phytohormone of fruits and plants. Presently, ethylene is primarily measured with stationary equipment in laboratories. Applying in situ measurement at the point of natural ethylene generation has been hampered by the lack of portable units designed to detect ethylene at necessary resolutions of a few parts per billion. Moreover, high humidity inside controlled atmosphere stores or containers complicates the realization of gas sensing systems that are sufficiently sensitive, reliable, robust and cost efficient. In particular, three measurement principles have shown promising potential for fruit supply chains and were used to develop independent mobile devices: non-dispersive infrared spectroscopy, miniaturized gas chromatography and electrochemical measurement. In this paper, the measurement systems for ethylene are compared with regard to the needs in fruit logistics; i.e. sensitivity, selectivity, long-term stability, facilitation of automated measurement and suitability for mobile application. Resolutions of 20–10 ppb can be achieved in mobile applications with state-of-the-art equipment, operating with the three methods described in the following. The prices of these systems are in a range below €10 000.

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Section: (A) Photoacoustic Spectroscopymentioning

confidence: 99%

Ethylene detection in fruit supply chains

Janssen

Schmitt

Blanke

et al. 2014

Phil. Trans. R. Soc. A.

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“…In 1880, Alexander Graham Bell discovered the PA effect. 17 Because of the advantages of this method, after Alexander Graham Bell, this method was developed by various scientists such as Kreuaer 18 ; Viengerov 19 (in order to detect by IR source with high noise); Schafer et al 20 (in order to increase the quality factor of PA cells); Kerr and Atwood 21 (in order to measure the absorption spectrum of water vapor); Bernegger and Sigrist 22 (performed PA spectroscopy of gases and vapors for trace gas analysis); Besson et al 23,24 (provided PA spectroscopy setup by diode laser in order to detect CH 4 and HCl); Gondal and Yamani 25 (for ozone detection); Lima et al 26 (for high-sensitivity detection of 16 ppb ethylene and 42 ppb ammonia); Kumar et al 27,28 (to trace hazardous chemicals by Quantum cascade lasers (QCLs)); Mohebbifar et al 29 and Dibaee et al 30 (in order to obtain high-sensitive spectroscopy of SO 2 , NO 2 , and SF 6 ); Yufei Ma 31 and Yufei Ma et al 32 (for ppb-level detection of ammonia based on QEPAS); and so forth. [33][34][35][36] The PA spectroscopy is based on the absorption of light by the gas.…”

Section: Theory Of Pa Spectroscopymentioning

confidence: 99%

High‐sensitivity detection and quantification of CHCl₃ vapors in various gas environments based on the photoacoustic spectroscopy

Mohebbifar

2019

Micro & Optical Tech Letters

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In this study, the quality factor and cell constant vs acoustic resonator sizes in the first radial and longitudinal modes were calculated using our homemade simulation. Based on these simulations a photoacoustic (PA) spectroscopy system was designed, optimized, and finally fabricated as a high‐sensitivity gas sensor. The subsequent experiments have been done to online monitoring of the trichloromethane (CHCl3) vapors trace. The sensitivity of system for detection of CHCl3 vapors was measured 488 ppb. Corresponding PA signal for different concentrations of CHCl3 vapors is determined in the presence of N2, synthetic air, He, and Ar in various gas environments. It is shown that the effect of buffer gas and the relevant pressures are substantiated to achieve the minimum detectable concentration. In other words, using heavier gases at the same experimental conditions lead to detection of the lower concentrations. When the buffer gas of system was He, the lowest PA signal was recorded. This faint signal of He is due to vibrational‐translational processes of He, thermodynamic and acoustic properties of system such as cell constant, quality factor, speed of sound, thermal diffusion, thermal boundary layer, and viscous boundary layer for He. These properties for various buffer gases were calculated and discussed.

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“…One of the most popular optical gas sensors is infrared laser-based gas sensors that converts electromagnetic radiation energy into electrical signals. CO or CO 2 lasers are preferentially used to selectively excite the specific molecules and in association with detection techniques 27 – 30 , such as photoacoustic spectroscopy results infast detection at low concentrations. Laser photoacoustic spectroscopy (LPAS) techniques offers detection limits that are very hard to achieve with other methods.…”

Section: Introductionmentioning

confidence: 99%

Non-destructive methods for fruit quality evaluation

Bratu

Popa

Bojan

et al. 2021

Sci Rep

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This work studies the evolution in time of several varieties of apples with application in quality storage maintenance. Two different methods were used to evaluate long-stored apples for better sorting and degradation assessment. The first method was laser photoacoustic spectroscopy for the detection of ethylene and ethanol compounds from the internal atmosphere of apples. The second method was multispectral imaging that measures the image and the spectrum combined and also can be used to address features such as ripening and external defects. The experiments showed that, the ethylene value decreases and the value of ethanol increases, which sometimes we may associate with a drift of the images toward darker tones, because the apple is slowly degrading. Non-invasive, real-time inspection can reveal when the degradation process begins, improving the capability of sorting, maintaining their quality and storability.

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Photoacoustic spectroscopy of CO₂laser in the detection of gaseous molecules

Cited by 4 publications

References 24 publications

Ethylene detection in fruit supply chains

Ethylene detection in fruit supply chains

High‐sensitivity detection and quantification of CHCl₃ vapors in various gas environments based on the photoacoustic spectroscopy

Non-destructive methods for fruit quality evaluation

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Photoacoustic spectroscopy of CO2laser in the detection of gaseous molecules

Cited by 4 publications

References 24 publications

Ethylene detection in fruit supply chains

Ethylene detection in fruit supply chains

High‐sensitivity detection and quantification of CHCl3 vapors in various gas environments based on the photoacoustic spectroscopy

Non-destructive methods for fruit quality evaluation

Contact Info

Product

Resources

About

Photoacoustic spectroscopy of CO₂laser in the detection of gaseous molecules

High‐sensitivity detection and quantification of CHCl₃ vapors in various gas environments based on the photoacoustic spectroscopy