High-accuracy low-water-content measurement of crude oil based on a near-infrared spectral absorption method

Abstract. This work describes the latest design, calibration and application of a near-infrared laser diode-based photoacoustic (PA) hygrometer developed for total water content measurement in simulated atmospheric freezing precipitation and high ice water content conditions with relevance in fundamental icing research, aviation testing, and certification. The single-wavelength and single-pass PA absorption cell is calibrated for molar water vapor fractions with a two-pressure humidity generator integrated into the instrument. Laboratory calibration showed an estimated measurement accuracy better than 3.3 % in the water vapor mole fraction range of 510–12 360 ppm (5 % from 250–21 200 ppm) with a theoretical limit of detection (3σ) of 3.2 ppm. The hygrometer is examined in combination with a basic isokinetic evaporator probe (IKP) and sampling system designed for icing wind tunnel applications, for which a general description of total condensed water content (CWC) measurements and uncertainties are presented. Despite the current limitation of the IKP to a hydrometeor mass flux below 90 gm-2s-1, a CWC measurement accuracy better than 20 % is achieved by the instrument above a CWC of 0.14 g m−3 in cold air (−30 ∘C) with suitable background humidity measurement. Results of a comparison to the Cranfield University IKP instrument in freezing drizzle and rain show a CWC agreement of the two instruments within 20 %, which demonstrates the potential of PA hygrometers for water content measurement in atmospheric icing conditions.

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Absorption spectra of human fetal and adult oxyhemoglobin, de-oxyhemoglobin, carboxyhemoglobin, and methemoglobin

Clinical Chemistry ◽

10.1093/clinchem/37.9.1633 ◽

1991 ◽

Vol 37 (9) ◽

pp. 1633-1638 ◽

Cited By ~ 380

Author(s):

W G Zijlstra ◽

A Buursma ◽

W P Meeuwsen-van der Roest

Keyword(s):

Turning Point ◽

Near Infrared ◽

Fetal Hemoglobin ◽

Spectral Absorption ◽

Low Oxygen ◽

Infrared Spectral Range ◽

Infrared Spectral ◽

Adult Hemoglobin ◽

Derivatives Of ◽

Pulse Oximeters

Abstract We determined the millimolar absorptivities of the four clinically relevant derivatives of fetal and adult human hemoglobin in the visible and near-infrared spectral range (450-1000 nm). As expected, spectral absorption curves of similar shape were found, but the small differences between fetal and adult hemoglobin absorptivity were important enough that they should be taken into account in multicomponent analysis of hemoglobin derivatives. Common pulse oximeters, however, involving light of 660 and 940 nm, are so insensitive to the presence of fetal hemoglobin that they can be used safely in neonates. The error in pulse oximetry caused by the presence of carboxyhemoglobin is insubstantial, but methemoglobin gives either an understimation or an overestimation at high or low oxygen saturation, respectively, the turning point being near 70% saturation.

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Bioagriculture Outlier Elimination Based on 3D View ofX-YVariance and Leverage Measurement

Mathematical Problems in Engineering ◽

10.1155/2015/375827 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Weizheng Shen ◽

Qingming Kong ◽

Jianbo Wang ◽

Nan Ji ◽

Zhongbin Su

Keyword(s):

Statistical Analysis ◽

Predictive Modeling ◽

Mahalanobis Distance ◽

Time Complexity ◽

Near Infrared ◽

High Accuracy ◽

Elimination Method ◽

Infrared Spectral

Aiming at effective outlier elimination in the biological near-infrared spectral and achieving high accuracy predictive modeling, this paper proposes a novel outlier elimination method based onX-Yvariance and leverage analysis. Firstly, the characters of near-infrared spectral are summarized; then residual sampleX-variance, leverage, and residual sampleY-variance are concatenated as a divergence measurement. We further compared the proposed method withX-Yvariance, Mahalanobis distance, and HotellingT2statistical analysis; the experiment results demonstrate that the proposed methods have competitive outlier elimination and better performance in time complexity and accuracy. The proposed method can also be adopted for other outlier elimination tasks.

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Research on visible and near infrared spectral-polarimetric properties of soil polluted by crude oil

AOPC 2017: Optical Spectroscopy and Imaging ◽

10.1117/12.2283314 ◽

2017 ◽

Author(s):

Pucheng Zhou ◽

Hui-yan Shen ◽

Bang-long Pan

Keyword(s):

Crude Oil ◽

Near Infrared ◽

Infrared Spectral ◽

Properties Of Soil

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The application in infrared spectral absorption method of methane detection technology

2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering ◽

10.1109/cmce.2010.5610262 ◽

2010 ◽

Author(s):

Li HaiFu ◽

Pei Ning

Keyword(s):

Absorption Method ◽

Spectral Absorption ◽

Detection Technology ◽

Infrared Spectral ◽

Methane Detection

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Photoacoustic hygrometer for icing wind tunnel water content measurement: Design, analysis and intercomparison

10.5194/amt-2020-295 ◽

2020 ◽

Author(s):

Benjamin Lang ◽

Wolfgang Breitfuss ◽

Simon Schweighart ◽

Philipp Breitegger ◽

Hugo Pervier ◽

...

Keyword(s):

Water Vapor ◽

Wind Tunnel ◽

Water Content ◽

Measurement Accuracy ◽

Near Infrared ◽

Limit Of Detection ◽

General Description ◽

Sampling System ◽

Content Measurement ◽

Better Than

Abstract. This work describes the latest design, calibration and application of a near-infrared laser diode-based photoacoustic (PA) hygrometer, developed for total water content measurement in simulated atmospheric freezing precipitation and high ice water content conditions with relevance in fundamental icing research, as well as aviation testing and certification. The single-wavelength and single-pass PA absorption cell is calibrated for molar water vapor fractions with a two-pressure humidity generator integrated into the instrument. Laboratory calibration showed an estimated measurement accuracy better than 3.3 % in the water vapor mole fraction range of 510–12,360 ppm (5 % from 250–21,200 ppm) with a theoretical limit of detection (3 sigma) of 3.2 ppm. The hygrometer is examined in combination with a basic isokinetic evaporator probe (IKP) and sampling system designed for icing wind tunnel application, for which a general description of total condensed water content (CWC) measurement and uncertainties are presented. Despite the current limitation of the IKP to a hydrometeor mass flux below 90 g m−2 s−1, a CWC measurement accuracy better than 20 % is achieved by the instrument above a CWC of 0.14 g m−3 in cold air (−30 °C) with suitable background humidity measurement. Results of a comparison to the Cranfield University IKP instrument in freezing drizzle and rain show a CWC agreement of the two instruments within 20 %, which demonstrates the potential of PA hygrometers for water content measurement in atmospheric icing conditions.

Download Full-text