Nonlinearity of absorbance with sample concentration and path length in evanescent wave spectroscopy using optical fiber sensors

Ruddy, Vincent P.

doi:10.1117/12.187023

Cited by 15 publications

(12 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A linear dependence between these two variables is true only for a certain concentration range. 10,11 The penetration depth of the evanescent wave, which relates to the absorption pathlength, changes as a function of the refractive index of the absorption medium . Thus, in evanescent-eld absorption, the absorbance of theber-optic sensor is related not only to the analyte's concentration but also to the refractive index of the solution.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

NIR Fiber-Optic Method with Multivariate Calibration Analysis for Determination of Inorganic Compounds in Aqueous Solutions

et al. 2000

View full text Add to dashboard Cite

Near-infrared spectra of aqueous solutions were collected by using evanescent-field fiber-optic sensors. The spectra of two- and four-electrolyte solutions were analyzed with a partial least-squares (PLS) algorithm to quantify the measurements. Our results indicate that the electrolytes can be identified and simultaneously determined by using the PLS calibration model. Electrolytes in opaque aqueous mixtures were also studied, and the results are compared with results from clear aqueous solutions.

show abstract

Section: Resultsmentioning

confidence: 99%

“…By combining evanescent-wave measurement with ber optics, one can m ake an inexpensive, robust sensor for m easurement of electrolytes in aqueous solutions. Evanescent-wave spectroscopy is discussed in other publications, 10,11 and the details will not be addressed here.…”

Section: Introductionmentioning

confidence: 99%

NIR Fiber-Optic Method with Multivariate Calibration Analysis for Determination of Inorganic Compounds in Aqueous Solutions

et al. 2000

View full text Add to dashboard Cite

show abstract

“…205 Most of these fibres require removal of the cladding in order to be used for internal reflection measurement. The unclad region is replaced by a layer of the absorbing medium whose properties have to be measured.…”

Section: Liver Tissue and Bacteria Biofilmsmentioning

confidence: 99%

Process monitoring of fibre reinforced composites using optical fibre sensors

Fernando¹,

Degamber²

2006

International Materials Reviews

View full text Add to dashboard Cite

The deployment of optical fibre based sensor systems for process monitoring of advanced fibre reinforced organic matrix composites is reviewed. The focus is on thermosetting resins and the various optical and spectroscopy-based techniques that can be used to monitor the processing of these materials. Following brief consideration of the manufacturing methods commonly used in the production of thermoset based composites, a discussion is presented on sensor systems that can be used to facilitate real-time chemical process monitoring. Although the focus is on thermosets, the techniques described can be adapted for chemical monitoring of organic species in general. Glossary of terms usedAFRC advanced fibre reinforced composites ATIR attenuated total internal reflectance ATR attenuated total reflectance CCD charged coupled device CRL charge recombination luminescence DDM diaminophenylmethane DDS diaminophenylsulphone DGEBA diglycidyl ether of bisphenol-A DICY dicyandiamide DMA dynamic mechanical analysis DMTA dynamic mechanical thermal analysis DRS diffuse reflectance spectroscopy DSC differential scanning calorimetry DTA differential thermal analysis EFPI extrinsic Fabry-Perot interferometric FBG fibre Bragg grating FTIR Fourier transform infrared HMGF heavy metal glass fibre IR infrared LED light emitting diode MCVD modified chemical vapour deposition MEA monoethylamine NA numerical aperture NIR near infrared NMR nuclear magnetic resonance OD outer diameter PCS plastic-clad silica PEEK polyether ether ketone PTFE polytetrafluoroethylene SLD super-luminescent diode SMA standard sub-miniature adaptor TGA thermogravimetric analysis TGDDM tetraglycidyl-4,49-diaminophenyl methane (also TGMDA) TMA thermomechanical analysis UV ultraviolet VNA vector network analyser

show abstract

“…The large diameter (600 m m) ® bers demonstrated little in¯uence on orientation of the ® ber to the launching optics of the FT-IR, since the angle of acceptance of the 0.37 NA ® bers was greater than the angle of light from the lens. 3,4 Sensors with a single bend are useful for analyzing small volum es of liquids that have relatively strong absorption bands by placing the apex of the bend in contact with the sample. The coiled sensors typically have two or three loops with a diameter of less than 1 cm.…”

Section: Exp Erim Entalmentioning

confidence: 99%