Optical path length and absorption cross section optimization for high sensitivity ozone concentration measurement

Marcus, Tay Ching En; Ibrahim, Mohd Haniff; Ngajikin, Nor Hafizah; Azmi, Asrul Izam

doi:10.1016/j.snb.2015.07.005

Cited by 16 publications

(11 citation statements)

References 14 publications

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“…At the second and subsequent iterations, we perform the same procedure until the condition (7th) is satisfied [20]. The polynomial obtained at the last iteration will be considered the autofluorescence background.…”

Section: Analyzing the Spectral Properties Of Aromatic Compounds In Gases Using The Improved Methodsmentioning

confidence: 99%

Application Of Mathematical Models And Digital Filters And Their Processors Of Spectral Analysis For Aromatic Compounds Gas In A Fluorescent Chemical

Zeyad¹

2021

TURCOMAT

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In this work, different spectra processing methods are affected by the principal components (Aromatic compounds). Keeping up high-spatial objectives is progressively basic, Various methodologies are utilized to check fragrant compounds that anticipate choosing a specific technique that's amid research Center determinations. These techniques empower us to assess a particular degree of normal compounds, much the same as benzene, toluene and xylene, and so on. One notable part of all types of signal systems is the flexibility of adaptation. And spatial exactness isn't fundamental to get a range from an expansive number of fragrant compounds where more prominent characterization and statistical mean are more critical. Moreover, sufficiently low deviations of the expected values were achieved from the true values. The standard deviation, to determine the properties of fragrant compounds and compare them with normal compounds isn't thorough. A persistent baseline rectification was performed; after that, the rectified spectrum was normalized to their area and somewhat smoothed. The autofluorescence foundation was subtracted, for the pure range analysis, by utilizing scientific approaches: polynomial estimation (PolyFit) and (method Processors Gases Improved). The accuracy obtained is not extreme and can be increased by developing algorithms and selecting other parameters. It is also possible to increase the accuracy and reliability of this method by improving the quality of the training sample by eliminating the unwanted data that we have obtained, by increasing the sample size, and by studying more in detail the sample data to eliminate inaccuracies that arise during the transition between concentrations Gas.

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Section: Analyzing the Spectral Properties Of Aromatic Compounds In Gases Using The Improved Methodsmentioning

confidence: 99%

Application Of Mathematical Models And Digital Filters And Their Processors Of Spectral Analysis For Aromatic Compounds Gas In A Fluorescent Chemical

Zeyad¹

2021

TURCOMAT

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“…First, we set the wavelength to 257.34 nm and 279.95 nm on the gas cell simulator (For each of the absorption wavelengths we simulate results). Second, the pressure and concentration were fixed at 1013.25mbar and 950ppm respectively [9], [12]. Third, values of optical path-length were then inserted beginning from 0.75cm -130cm while the temperature was then varied from 100K -350K for each optical path-length.…”

Section: Simulation and Methodologymentioning

confidence: 99%

“…Of the afore mention bands, the Hartley band has the strongest absorption of light in the UV spectrum, hence a high OACS [10] Therefore, ozone gas concentration in the atmosphere could be efficiently measured in the Hartley band (between 200 to 300 nm). 257.34 nm [11] and 279.95 nm [12] being in the Hartley band have also shown strong absorption cross section of ozone in the UV. To a large extent, in the Hartley band, ozone gas has a unique property that allows very strong absorption of UV radiation.…”

Section: Introductionmentioning

confidence: 91%

Combined Effects of Temperature and Optical Path-Length on Ozone Gas Absorption Cross Section at 257.34nm and 279.95nm in Relation to Green Communications

Patrick

David²,

Alenoghena³

et al. 2021

IJOP

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The value of ozone absorption cross section (OACS) is a key parameter used in the configuration of gas sensors. Sadly, the variations of certain parameters among others such as temperature, pressure, and optical pathlength in a given spectrum can affect the values of OACS. As a result, there have been several discrepancies in the value of OACS. Recently, the simultaneous effects of optical path-length were investigated in the visible spectrum. Hence, there is the need to also carry out the same investigation in the UV spectrum. So, in this paper, we have reported the combined variation effects of temperature (100 K-350 K), and optical path-length (0.75 cm-130 cm) on OACS in the UV spectrum. We used the method of optical absorption spectroscopy as deployed in a model software called Spectralcalc. The software comprising the HITRAN12 latest line list was used to simulate OACS values. Simulated results were obtained using the latest available line list on the HITRAN12 Spectralcalc simulator. Our obtained results were slightly different from those reported for the visible spectrum but followed a similar trend, in that it showed a decrease in the OACS with an increase in the temperature from 100 K to 350 K at 279.95 nm and 257.34 nm by 1.09 % and 1.43 % respectively. While optical path-length had zero effect on it. We, therefore, conclude that at constant pressure, OACS depends on both temperature and absorption wavelength but not on optical path-length. The analysis reported in this work only seeks to address the differences in the OACS relative to temperature in the UV spectrum. So, the results obtained in this paper can be used to optimally configure ozone gas sensors to obtain an accurate measurement.

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“…However, the sensor saturation may occur, which may limit the sensitivity and linearity. Marcus et al [20] investigated the sensor saturation and derived equations based on Beer–Lambert law for optimized transmittance, optical path length, and absorption cross-section for a specific range of ozone concentration to prevent sensor saturation. The optimized optical path length, l op and optimized cross-section σ op for ozone concentrations c 1 and c 2 were derived as expressed as, lop=106 R T false(lnc1−lnc2false)σ NAP (c1−c2); σop=106 R T false(lnc1−lnc2false)l NAP (c1−c2) whereas c is the concentration of an analyte in ppm; σ is absorption cross-section in m 2 -molecule −1 ; T is absolute temperature in K ; P is pressure in atm; R is ideal gas constant, 8.205746 × 10 −5 atm-m 3 mol −1 - K −1 ; N A is Avogadro’s constant, 6.02214199 × 10 23 molecule-mol −1 .…”

Section: Uv Spectrophotometrymentioning

confidence: 99%

Gas Detection Using Portable Deep-UV Absorption Spectrophotometry: A Review

Khan

Newport

Calvé

2019

Sensors

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Several gas molecules of environmental and domestic significance exhibit a strong deep-UV absorption. Therefore, a sensitive and a selective gas detector based on this unique molecular property (i.e., absorption at a specific wavelength) can be developed using deep-UV absorption spectrophotometry. UV absorption spectrometry provides a highly sensitive, reliable, self-referenced, and selective approach for gas sensing. This review article addresses the recent progress in the application of deep-UV absorption for gas sensing owing to its inherent features and tremendous potentials. Applications, advancements, and challenges related to UV emission sources, gas cells, and UV photodetectors are assessed and compared. We present the relevant theoretical aspects and challenges associated with the development of portable sensitive spectrophotometer. Finally, the applications of UV absorption spectrometry for ozone, NO2, SO2, and aromatic organic compounds during the last decades are discussed and compared. A portable UV absorption spectrophotometer can be developed by using LEDs, hollow core waveguides (HCW), and UV photodetectors (i.e., photodiodes). LED provides a portable UV emission source with low power input, low-intensity drifts, low cost, and ease of alignment. It is a quasi-chromatic UV source and covers the absorption band of molecules without optical filters for absorbance measurement of a target analyte. HCWs can be applied as a miniature gas cell for guiding UV radiation for measurement of low gas concentrations. Photodiodes, on the other hand, offer a portable UV photodetector with excellent spectral selectivity with visible rejection, minimal dark current, linearity, and resistance against UV-aging.

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Optical path length and absorption cross section optimization for high sensitivity ozone concentration measurement

Cited by 16 publications

References 14 publications

Application Of Mathematical Models And Digital Filters And Their Processors Of Spectral Analysis For Aromatic Compounds Gas In A Fluorescent Chemical

Application Of Mathematical Models And Digital Filters And Their Processors Of Spectral Analysis For Aromatic Compounds Gas In A Fluorescent Chemical

Combined Effects of Temperature and Optical Path-Length on Ozone Gas Absorption Cross Section at 257.34nm and 279.95nm in Relation to Green Communications

Gas Detection Using Portable Deep-UV Absorption Spectrophotometry: A Review

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