Simultaneous detection of CO2 and CO in engine exhaust using multi-mode absorption spectroscopy, MUMAS

Thompson, Alexander W. J.; Northern, Henry; Williams, B. A. O.; Hamilton, Michelle L.; Ewart, Paul

doi:10.1016/j.snb.2014.03.060

Cited by 20 publications

(15 citation statements)

References 27 publications

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“…Previously, MUMAS has been demonstrated for the measurement of concentration, temperature and pressure of molecular oxygen using multi-mode near-IR diode lasers [18], the detection of C 2 H 2 [20], CO and CO 2 [21] using an Er:Yb:glass microlaser, as well as the simultaneous detection of C 2 H 2 , CH 4 and N 2 O in the 1.5 μm region [22]. Extension to the important mid-IR range between 3 and 4 μm was demonstrated using a difference frequency generation, DFG, system based on the Er:Yb:glass microlaser for the simultaneous detection of CH 4 and NH 3 [23].…”

Section: Introductionmentioning

confidence: 99%

Multi-species sensing using multi-mode absorption spectroscopy with mid-infrared interband cascade lasers

et al. 2016

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Section: Introductionmentioning

confidence: 99%

Multi-species sensing using multi-mode absorption spectroscopy with mid-infrared interband cascade lasers

et al. 2016

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“…In some previous demonstrations of MUMAS, the mode linewidth, of the order of several MHz, was insignificant compared to the Doppler and pressure-broadened absorption lines (of order GHz) and so was not a critical parameter in the model [18,20]. In the case of a multi-mode interband cascade laser, ICL, �ν width was measured using MUMAS signatures of a molecule with widely spaced absorption lines so that a feature could be identified as arising from the interaction of a single individual mode with one spectral line [23].…”

Section: Measurement Of Mode Linewidth �ν Widthmentioning

confidence: 93%

“…Nonetheless, applications that do not require the ultimate in detection sensitivity, such as in chemical reaction or industrial process monitoring or where target species are present in concentrations in the range of 10 ppmv or above, can benefit from the multi-species sensing capability and rapid response time available from MUMAS. Multi-species detection by MUMAS has been demonstrated in the near-and mid-infrared using a custom-built Er/Yb/glass microlaser at 1.5 μm, difference frequency generation, DFG, and, more recently, an interband cascade laser, ICL, in the 3-4 μm range [19][20][21][22][23]. Detected species in mixtures include, CO, CO 2 , CH 4 , C 2 H 2 , H 2 CO, NH 3 , N 2 O and H 2 O.…”

Section: Introductionmentioning

confidence: 99%

Multi-mode absorption spectroscopy using a quantum cascade laser for simultaneous detection of NO and H2O

et al. 2016

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cascade lasers, QCLs. The high resolution available using single-mode devices provides high sensitivity with minimum detection limits in the range of ppbv in some applications. The limited range of mode-hop-free, MHF, tuning of most single-mode lasers, however, often restricts TDLAS methods to detection of a single species unless, fortuitously, two species have transitions lying within the MHF range. Detection of more than one species using TDLAS usually involves multiplexing several lasers and detector systems [4]. Widely tunable external cavity diode lasers, emitting narrow line or single-mode outputs, have recently been demonstrated in the 4-10 μm mid-infrared range based on quantum cascade devices but the relatively slow tuning rates limit application in rapidly changing environments [5]. A variety of broadband spectroscopy methods have been developed that allow detection of multiple species over a wide spectral range but not all are available in the mid-IR. These include use of multi-section diodes, broadband or wavelength agile light sources and correlation spectroscopic methods [6][7][8][9][10][11][12]. The wide bandwidth "frequency combs" available from mode-locked lasers has been exploited for broadband spectroscopy but usually involve complex laser systems and high resolution dispersion optics [13,14]. Extension of comb-based spectroscopy to the mid-infrared beyond 4 μm is becoming possible with the development of frequency combs based on QCL devices. A comb of width 100 cm −1 has recently been demonstrated at 7 μm [15]. Heterodyne methods, with potential for multi-species sensing, have also been demonstrated to allow detection in the RF region at the cost of some additional complexity and restriction in width of the spectrum covered [16].The technique of multi-mode absorption spectroscopy, MUMAS, addresses some of the limitations of TDLAS, specifically by providing wide spectral coverage whilst Abstract Detection of multiple transitions in NO and H 2 O using multi-mode absorption spectroscopy, MUMAS, with a quantum cascade laser, QCL, operating at 5.3 μm at scan rates up to 10 kHz is reported. The linewidth of longitudinal modes of the QCL is derived from pressure-dependent fits to experimental MUMAS data. Variations in the spectral structure of the broadband, multi-mode, output of the commercially available QCL employed are analysed to provide accurate fits of modelled MUMAS signatures to the experimental data.

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“…Furthermore, the greenhouse environment has its own special working conditions and required detection range for CO 2 . The existing infrared sensing techniques involve photoacoustic spectroscopy (PAS) [13], tunable diode laser absorption spectroscopy (TDLAS) [14][15][16][17], and direct absorption spectroscopy (DAS) [18]. PAS is one of the most famous spectroscopy techniques for trace gas detection because of its high sensitivity and selectivity.…”

Section: Introductionmentioning

confidence: 99%

Mid-infrared absorption-spectroscopy-based carbon dioxide sensor network in greenhouse agriculture: development and deployment

et al. 2016

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A mid-infrared carbon dioxide (CO₂) sensor was experimentally demonstrated for application in a greenhouse farm environment. An optical module was developed using a lamp source, a dual-channel pyre-electrical detector, and a spherical mirror. A multi-pass gas chamber and a dual-channel detection method were adopted to effectively enhance light collection efficiency and suppress environmental influences. The moisture-proof function realized by a breathable waterproof chamber was specially designed for the application of such a sensor in a greenhouse with high humidity. Sensor structure of the optical part and electrical part were described, respectively, and related experiments were carried out to evaluate the sensor performance on CO₂ concentration. The limit of detection of the sensor is 30 ppm with an absorption length of 30 cm. The relative detection error is less than 5% within the measurement range of 30-5000 ppm. The fluctuations for the long-term (10 h) stability measurements on a 500 ppm CO₂ sample and a 2000 ppm CO₂ sample are 1.08% and 3.6%, respectively, indicating a good stability of the sensor. A wireless sensor network-based automatic monitoring system was implemented for greenhouse application using multiple mid-infrared CO₂ sensor nodes. A monitor software based on LabVIEW was realized via a laptop for real-time environmental data display, storage, and website sharing capabilities. A field experiment of the sensor network was carried out in the town of Shelin in Jilin Province, China, which proved that the whole monitoring system possesses stable sensing performance for practical application under the circumstances of a greenhouse.

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Simultaneous detection of CO2 and CO in engine exhaust using multi-mode absorption spectroscopy, MUMAS

Cited by 20 publications

References 27 publications

Multi-species sensing using multi-mode absorption spectroscopy with mid-infrared interband cascade lasers

Multi-species sensing using multi-mode absorption spectroscopy with mid-infrared interband cascade lasers

Multi-mode absorption spectroscopy using a quantum cascade laser for simultaneous detection of NO and H2O

Mid-infrared absorption-spectroscopy-based carbon dioxide sensor network in greenhouse agriculture: development and deployment

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