Performance of a near Infrared Spectrometer Equipped with an Autosampling Accessory

2003 ◽  
Vol 11 (2) ◽  
pp. 83-95
Author(s):  
Nathalie Szydlowski-Zanier ◽  
Marc Berger ◽  
François Wahl ◽  
Denis Guillaume
Keyword(s):  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Cetane Number ◽  
Chemical Properties ◽  
Signal To Noise ◽  
Physico Chemical ◽  
Infrared Spectrometer ◽  
The Stability ◽  
Near Infrared Spectrometer

The performance of a Fourier-transform near infrared (FT-NIR) spectrometer equipped with an autosampling accessory (AutoSamplIR) using disposable vials with uncontrolled pathlength has been compared with the performance of an FT-NIR equipped with a manual vial sampling accessory using a reusable cell with calibrated pathlength. The effect of different parameters such as the signal-to-noise ratio, the stability of the purge and the linearity of absorbance have been evaluated by means of the NIR predictions of two physico-chemical properties of interest for gasoils, i.e the wt% of hydrogen and the cetane number (CN). It has been shown that an FT-NIR with the autosampling accessory can be used advantageously at low cost for quick and precise analyses of small amounts of sample.

scholarly journals Miniaturized NIR Spectrometer Based on Novel MOEMS Scanning Tilted Grating

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 478 ◽  
Author(s):  
Jian Huang ◽  
Quan Wen ◽  
Qiuyu Nie ◽  
Fei Chang ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Closed Loop ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Measuring Time ◽  
Loop Control ◽  
Infrared Spectrometer ◽  
Potential Alternative ◽  
Near Infrared Spectrometer ◽  
Better Than

This paper presents a dispersive near-infrared spectrometer with features of miniaturization, portability and low cost. The application of a resonantly-driven scanning grating mirror (SGM) as a dispersive element in a crossed Czerny–Turner configuration enables the design of a miniaturized spectrometer that can detect the full spectra using only one single InGaAs diode. In addition, a high accuracy recalculation is realized, which can convert time-dependent measurements to spectrum information by utilizing the deflection position detector integrated on SGM and its associated closed-loop control circuit. Finally, the spectrometer prototype is subjected to a series of tests to characterize the instrument’s performance fully. The results of the experiment show that the spectrometer works in a spectral range of 800 nm–1800 nm with a resolution of less than 10 nm, a size of 9 × 7 × 7 cm3, a wavelength stability better than ±1 nm and a measuring time of less than 1 ms. Furthermore, the power consumption of the instrument is 3 W at 5 V DC, and the signal-to-noise ratio is 3267 at full scale. Therefore, this spectrometer could be a potential alternative to classical spectrometers in process control applications or could be used as a portable or airborne spectroscopic sensor.

scholarly journals The Improvement on the Performance of DMD Hadamard Transform Near-Infrared Spectrometer by Double Filter Strategy and a New Hadamard Mask

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 149 ◽  
Author(s):  
Zifeng Lu ◽  
Jinghang Zhang ◽  
Hua Liu ◽  
Jialin Xu ◽  
Jinhuan Li
Keyword(s):  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Nonuniform Distribution ◽  
Stray Light ◽  
Spectral Energy ◽  
Hadamard Transform ◽  
Digital Micromirror Device ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer ◽  
The Impact

In the Hadamard transform (HT) near-infrared (NIR) spectrometer, there are defects that can create a nonuniform distribution of spectral energy, significantly influencing the absorbance of the whole spectrum, generating stray light, and making the signal-to-noise ratio (SNR) of the spectrum inconsistent. To address this issue and improve the performance of the digital micromirror device (DMD) Hadamard transform near-infrared spectrometer, a split waveband scan mode is proposed to mitigate the impact of the stray light, and a new Hadamard mask of variable-width stripes is put forward to improve the SNR of the spectrometer. The results of the simulations and experiments indicate that by the new scan mode and Hadamard mask, the influence of stray light is restrained and reduced. In addition, the SNR of the spectrometer also is increased.

scholarly journals Polymer Type Identification of Marine Plastic Litter Using a Miniature Near-Infrared Spectrometer (MicroNIR)

2020 ◽  
Vol 10 (23) ◽  
pp. 8707
Author(s):  
Svetlana Pakhomova ◽  
Igor Zhdanov ◽  
Bert van Bavel
Keyword(s):  
Marine Environment ◽  
Near Infrared ◽  
Low Cost ◽  
Visual Assessment ◽  
Correct Identification ◽  
Plastic Pollution ◽  
Spectra Analysis ◽  
Infrared Spectrometer ◽  
Site Identification ◽  
Near Infrared Spectrometer

Plastic pollution in the marine environment has turned into an important research topic in recent decades. Until recently, studies were often based on visual assessment only, which is not enough to draw any conclusion about the chemical nature of found plastic items and could lead to incorrect results. Standardized, fast, and efficient low-cost methods for marine plastic litter identification are urgently needed to monitor the occurrence and distribution worldwide. In this paper, we demonstrate that a miniaturized handheld near-infrared spectrometer—MicroNIR—can be used for on-site identification of different plastic polymers. A database containing polymer spectra of the most produced and reported polymer types in the marine environment was created including polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), polycarbonate (PC), polyurethane (PUR), and Silicone. Using spectral match value (SMV, included in the instrument software) for spectra analysis resulted in an accurate classification of all nine polymer types. The method was used for the identification of marine macro-, meso-, and microplastic litter collected on beaches in sediments and seawater and enabled the correct identification of marine plastic litter for macro-, meso- (96%), and microplastics (73%) with exception of totally black items and items less than 1 mm in size. The method and instrumentation presented here are very well suited to support “Citizen Science” marine litter monitoring projects during beach cleaning and similar activities.

Near-IR Multiplex Bandpass Spectrometer Utilizing Liquid Molecular Filters

1995 ◽  
Vol 49 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Andrew Fong ◽  
Gary M. Hieftje
Keyword(s):  
Propylene Glycol ◽  
High Throughput ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Ir Radiation ◽  
Near Ir ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer

A simple near-infrared spectrometer is described which uses common liquids as near-IR spectral filters. Each filter substance passes multiple bands of near-IR radiation. This new type of spectrometer offers simplicity, cost advantages, and enhanced throughput. The high throughput is useful for ensuring the high signal-to-noise ratio typically needed for chemometrics. The high throughput also allows the use of longer sample pathlengths. The performance of the spectrometer is demonstrated in the determination of methanol through a 1-cm pathlength of water and in the determination of trace amounts of water in organic solvents such as propylene glycol and dimethyl sulfoxide (DMSO). Best-case detection limits were 0.02% (w/w) methanol in water, 0.0006% water in DMSO, and 0.004% water in propylene glycol.

Near-Infrared Spectroscopy Signal Extraction and Processing Design

2013 ◽  
Vol 404 ◽  
pp. 555-559 ◽  
Author(s):  
Ke Zhao ◽  
Jian Hua Jiang ◽  
Jun Fang Fu ◽  
Jin Bo Xu
Keyword(s):  
Near Infrared ◽  
Experimental Testing ◽  
Signal To Noise Ratio ◽  
High Reliability ◽  
Digital Signal ◽  
Signal Extraction ◽  
Filter Method ◽  
Infrared Spectrometer ◽  
Filtering Function ◽  
Near Infrared Spectrometer

This paper introduces the MSP430 MCU-based near-infrared spectrometer front-end signal extraction and software signal processing design.The system adopts phase locked loop technology to signal phase shift processing. Phase sensitive filtering function achieved by the balance modem AD630.Finally the analog signal is converted to digital signal by AD7715 for the microprocessor processed.Microprocessor receives digital signal, filter processing is performed using a first order lag filter method to determine the point of measurement value.Through the comparison analysis of the experimental testing result, the program has higher signal-to-noise ratio and suppress interference ability, high reliability, good stability,etc.

Research of the Hadamard Multiplex Advantages Using a Programmable Micro-Mirror in a Near-Infrared Spectrometer

2011 ◽  
Vol 483 ◽  
pp. 417-421
Author(s):  
Yuan Jun Guo ◽  
Zhi Yu Wen ◽  
Zhi Hai Zhang ◽  
Wei Wang
Keyword(s):  
Near Infrared ◽  
Luminous Flux ◽  
Hadamard Transform ◽  
Weak Signal ◽  
Signal To Noise ◽  
Theoretic Result ◽  
S Matrix ◽  
Single Detector ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer

A programmable micro mirror has been used in a near infrared spectrometer in order to achieve the purpose of signal multiplexing, to solve the problem of low luminous flux when using single slit and to increase the signal-to-noise (SNR) ratio. Use Hadamard Transform (HT) and programmable micro mirror as its encoding mask to detect the whole spectrum with a single detector, research and analyze the enhancement of SNR of the weak signal. First of all, the mask symbol number is fixed as 63-order based on the Hadamard Transform principle, calculate the optimal S-Matrix, and then the encoding mask has been realized by micro mirror. At last, carry out some experimental verifications as well as data analyzing, discuss the alternating spectrum signal which produce an effect on transformational algorithm, bring out the coadded upswing plan. The result shows that: the conflict of resolution and SNR can be well settled with Hadamard multiplex. The SNR can be increased by the factor of 3.5, which is identical with the theoretic result.

scholarly journals Near-Infrared Transmission Spectroscopy of Aqueous Solutions: Influence of Optical Pathlength on Signal-To-Noise Ratio

2002 ◽  
Vol 56 (12) ◽  
pp. 1600-1606 ◽  
Author(s):  
Peter Snoer Jensen ◽  
Jimmy Bak
Keyword(s):  
Aqueous Solutions ◽  
Noise Level ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Pure Water ◽  
Optimal Choice ◽  
Infrared Transmission ◽  
Signal To Noise ◽  
Infrared Spectrometer ◽  
Noise Ratio

The optimal choice of optical pathlength, source intensity, and detector for near-infrared transmission measurements of trace components in aqueous solutions depends on the strong absorption of water. In this study we examine under which experimental circumstances one may increase the pathlength to obtain a measurement with higher signal-to-noise ratio. The noise level of measurements at eight different pathlengths from 0.2 to 2.0 mm of pure water and of 1 g/dL aqueous glucose signals were measured using a Fourier transform near-infrared spectrometer and a variable pathlength transmission cell. The measurements demonstrate that the noise level is determined by the water transmittance. The noise levels in the spectral region from 5000 to 4000 cm−1 show that the optimal pathlength (0.4 mm) is the same for pure water and 1 g/dL aqueous glucose solutions. When detector saturation occurs it is favorable to increase the pathlength instead of attenuating the light source. The obtained results are explained by an analytical model.

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