A compact NIR fiber-optic diode laser spectrometer for CO and CO2:

Engelbrecht, Rainer

doi:10.1016/j.saa.2003.11.033

Cited by 54 publications

(26 citation statements)

References 20 publications

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“…However, unlike previous investigators [3,4,6], we report here an alternative use of trigonometric series postulated by Gabor [8] for representation of an arbitrary elementary signal.…”

Section: Theoretical Modelmentioning

confidence: 88%

“…For analytical purposes it is always desirable to evaluate line-shape profile [3,4,5,6], rather then simply estimate peak-to-peak parameters of WMS signal, which contains less-robust information on molecular absorption and spectral broadening. Therefore, line-shape fitting procedure needs to be addressed in WMS post-processing scheme as the level of uncertainties is a critical attribute of measurement outputs.…”

Section: Introductionmentioning

confidence: 99%

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A new line-shape asymmetry model for wavelength modulation spectroscopy in gaseous flows

Nevrlý

Klečka

Vašínek

et al. 2018

Measurement Science Review

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This communication reports technical notes on the development and application of an automated line-shape fitting procedure for wavelength modulation spectroscopy (WMS). Near-infrared transitions of carbon dioxide (CO2) around 1573 nm were measured in vertical cold (nonreacting) flow of CO2 at atmospheric pressure using WMS with demodulation at second harmonic frequency. Semi-empirical model based on the set of so-called Gabor functions was developed and parameters of Lorentzian line-shape profile and its asymmetry resulting from simultaneous frequency and amplitude response of the current-modulated semiconductor laser were determined. Nonlinear least-square fitting procedure employing differential evolution algorithm was successfully utilized for performing this task. Line-shape fitting procedure enabling efficient signal de-noising and background subtraction of wavelength modulation spectra was implemented into an open-source code.

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“…However, unlike previous investigators [3,4,6], we report here an alternative use of trigonometric series postulated by Gabor [8] for representation of an arbitrary elementary signal.…”

Section: Theoretical Modelmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

A new line-shape asymmetry model for wavelength modulation spectroscopy in gaseous flows

Nevrlý

Klečka

Vašínek

et al. 2018

Measurement Science Review

View full text Add to dashboard Cite

show abstract

“…This method was abandoned and the method of fitting a sinewave to the peak locations from the etalon transmission was used instead to estimate the modulation depth and IM to FM phase shift which is shown in figure 6. [16, 68] The modulation depth is estimated to be 0.061 (5) cm −1 and the phase shift was determined to be about 1.46 (3) π radians. The uncertainties are shown in parenthesis and are k =2 type A.…”

Section: 1 Methodsmentioning

confidence: 99%

Towards a standard for the dynamic measurement of pressure based on laser absorption spectroscopy

Douglass

Olson

2016

Metrologia

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We describe an approach for creating a standard for the dynamic measurement of pressure based on the measurement of fundamental quantum properties of molecular systems. From the linewidth and intensities of ro-vibrational transitions we plan on making an accurate determination of pressure and temperature. The goal is to achieve an absolute uncertainty for time-varying pressure of 5 % with a measurement rate of 100 kHz, which will in the future serve as a method for the traceable calibration of pressure sensors used in transient processes. To illustrate this concept we have used wavelength modulation spectroscopy (WMS), due to inherent advantages over direct absorption spectroscopy, to perform rapid measurements of carbon dioxide in order to determine the pressure. The system records the full lineshape profile of a single ro-vibrational transition of CO2 at a repetition rate of 4 kHz and with a systematic measurement uncertainty of 12 % for the linewidth measurement. A series of pressures were measured at a rate of 400 Hz (10 averages) and from these measurements the linewidth was determined with a relative uncertainty of about 0.5 % on average. The pressures measured using WMS have an average difference of 0.6 % from the absolute pressure measured with a capacitance diaphragm sensor.

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“…Infrared CO sensing device [6][7][8][9][10][11] has the advantages of wide measuring range, fast response, high sensitivity, and good selectivity. Therefore, infrared absorption spectroscopy becomes the most popular detection technique.…”

mentioning

confidence: 99%

“…Therefore, infrared absorption spectroscopy becomes the most popular detection technique. The existing infrared sensing techniques can be classified into three types, namely, photoacoustic spectroscopy (PAS) [6] , wavelength modulation spectroscopy (WMS) or tunable diode laser absorption spectroscopy (TDLAS) [7][8][9][10] , and direct absorption spectroscopy (DAS) [11] . PAS-based detection system has high sensitivity, but it is not suitable for in-situ detection [6] .…”

mentioning

confidence: 99%

Mid-infrared carbon monoxide detection system using differential absorption spectroscopy technique

Dong

Sui

et al. 2015

Optoelectron. Lett.

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A differential carbon monoxide (CO) concentration sensing device using a self-fabricated spherical mirror (e.g. light-collector) and a multi-pass gas-chamber is presented in this paper. Single-source dual-channel detection method is adopted to suppress the interferences from light source, optical path and environmental changes. Detection principle of the device is described, and both the optical part and the electrical part are developed. Experiments are carried out to evaluate the sensing performance on CO concentration. The results indicate that at 1.013×10 5 Pa and 298 K, the limit of detection (LoD) is about 11.5 mg/m 3 with an absorption length of 40 cm. As the gas concentration gets larger than 115 mg/m 3 (1.013×10 5 Pa, 298 K), the relative detection error falls into the range of −1.7%-+1.9%. Based on 12 h long-term measurement on the 115 mg/m 3 and 1 150 mg/m 3 CO samples, the maximum detection errors are about 0.9% and 5.5%, respectively. Due to the low cost and competitive characteristics, the proposed device shows potential applications in CO detection in the circumstances of coal-mine production and environmental protection.

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A compact NIR fiber-optic diode laser spectrometer for CO and CO2:

Cited by 54 publications

References 20 publications

A new line-shape asymmetry model for wavelength modulation spectroscopy in gaseous flows

A new line-shape asymmetry model for wavelength modulation spectroscopy in gaseous flows

Towards a standard for the dynamic measurement of pressure based on laser absorption spectroscopy

Mid-infrared carbon monoxide detection system using differential absorption spectroscopy technique

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