Journal: Sensors (Basel, Switzerland)

Article Title: Standoff Detection and Identification of Liquid Chemicals on a Reflective Substrate Using a Wavelength-Tunable Quantum Cascade Laser

doi: 10.3390/s22093172

Figure Lengend Snippet: Normalized absorbance spectra of the analyte chemicals of ( a ) DEP and ( b ) DMMP in the EC-QCL operational wavenumber range. ( c ) Photograph images of DEP with surface density of 4 g/m 2 distributed on the substrates formed by grinding.

Article Snippet: Experiments were conducted using diethyl phthalate (DEP), a simulant of VX, and dimethyl methylphosphonate (DMMP), a simulant of G-agent [ ]. a,b show the normalized absorbance spectra of DEP and DMMP, respectively, obtained from the National Institute of Standards and Technology Chemistry WebBook [ ].

Techniques:

Journal: Sensors (Basel, Switzerland)

Article Title: Standoff Detection and Identification of Liquid Chemicals on a Reflective Substrate Using a Wavelength-Tunable Quantum Cascade Laser

doi: 10.3390/s22093172

Figure Lengend Snippet: ( a , b ) Measured (black) and calculated (red) diffuse reflection spectra for DEP coated substrate with Ra of 1.6 μm, at incidence angle of 5° for surface density of ( a ) 2 g/m 2 and ( b ) 4 g/m 2 . ( c , d ) Extracted power scaling factor ( c ) c 0 and extracted absorbance scaling factor ( d ) c DEP from measured data for different surface densities of DEP and different incidence angles using the substrate with Ra of 1.6 μm. ( e ) Distribution of the coefficient of determination R 2 according to c 0 . ( f ) Result of None, DEP, DMMP, and Mixture of DEP and DMMP.

Article Snippet: Experiments were conducted using diethyl phthalate (DEP), a simulant of VX, and dimethyl methylphosphonate (DMMP), a simulant of G-agent [ ]. a,b show the normalized absorbance spectra of DEP and DMMP, respectively, obtained from the National Institute of Standards and Technology Chemistry WebBook [ ].

Techniques:

Journal: Sensors (Basel, Switzerland)

Article Title: Standoff Detection and Identification of Liquid Chemicals on a Reflective Substrate Using a Wavelength-Tunable Quantum Cascade Laser

doi: 10.3390/s22093172

Figure Lengend Snippet: ( a ) Measured (black) and calculated (red) diffuse reflection spectra of DEP and DMMP 1:1 ratio mixture coated on substrate with Ra of 1.6 μm at incidence angle of 5° for surface density of 5 g/m 2 . ( b ) Calculated absorbance spectra of DEP (red), DMMP (blue), and 1:1 ratio mixture (black) using the extracted absorbance scaling factors in ( a ). ( c ) Absorbance scaling factors of DEP ( y -axis) and DMMP ( x -axis) for a surface density of 5 g/m 2 and different surface roughness of the substrate. ( d ) Absorbance scaling factors of DEP and DMMP for substrate roughness Ra of 1.6 μm, surface density of 5 g/m 2 according to incidence angle. ( e ) Result of classification of the mixture measurement data using the deep learning model trained for four classes of None, DEP, DMMP, and Mixture of DEP and DMMP.

Article Snippet: Experiments were conducted using diethyl phthalate (DEP), a simulant of VX, and dimethyl methylphosphonate (DMMP), a simulant of G-agent [ ]. a,b show the normalized absorbance spectra of DEP and DMMP, respectively, obtained from the National Institute of Standards and Technology Chemistry WebBook [ ].

Techniques: