Multi-Wavelength Determination of Total Ozone and Ultraviolet Irradiance

1982 ◽  
pp. 109-120
Author(s):  
Alex E. S. Green
Keyword(s):  
Total Ozone ◽  
Multi Wavelength ◽  
Ultraviolet Irradiance

scholarly journals Reliability of temperature determination from curve-fitting in multi-wavelength pyrometery

2013 ◽  
Vol 31 (2) ◽  
pp. 333-336
Author(s):  
P.A. Ni ◽  
R.M. More ◽  
F.M. Bieniosek
Keyword(s):  
Ion Beam ◽  
Dense Matter ◽  
Warm Dense Matter ◽  
Emission Data ◽  
Reliable Determination ◽  
Temperature Determination ◽  
Multi Wavelength ◽  
Fitting In ◽  
Hot Surface

AbstractThis paper examines the reliability of a widely used method for temperature determination by multi-wavelength pyrometry. In recent warm dense matter experiments with ion-beam heated metal foils, we found that the statistical quality of the fit to the measured data is not necessarily a measure of the accuracy of the inferred temperature. We found a specific example where a second-best fit leads to a more realistic temperature value. The physics issue is the wavelength-dependent emissivity of the hot surface. We discuss improvements of the multi-frequency pyrometry technique, which will give a more reliable determination of the temperature from emission data.

Multi-wavelength optical determination of black and brown carbon in atmospheric aerosols

2015 ◽  
Vol 108 ◽  
pp. 1-12 ◽  
Author(s):  
D. Massabò ◽  
L. Caponi ◽  
V. Bernardoni ◽  
M.C. Bove ◽  
P. Brotto ◽  
...  
Keyword(s):  
Atmospheric Aerosols ◽  
Brown Carbon ◽  
Multi Wavelength ◽  
Optical Determination

Multi-wavelength analyses of second-derivative spectra for rapid determination of acetaminophen in serum.

1988 ◽  
Vol 34 (6) ◽  
pp. 1119-1121 ◽  
Author(s):  
B Dingeon ◽  
M A Charvin ◽  
M T Quenard ◽  
H Thome
Keyword(s):  
Phosphate Buffer ◽  
Rapid Determination ◽  
Turnaround Time ◽  
Second Derivative ◽  
Derivative Spectra ◽  
Multi Wavelength ◽  
Precision And Accuracy ◽  
Second Derivative Spectra ◽  
Method Of Extraction

Abstract Measurement of acetaminophen by analysis of the second derivative of its spectrum is specific and sensitive. The method of extraction and the use of just one phosphate buffer as reagent makes this method very convenient. Readings are reliable from 10 to 1500 mg/L. A turnaround time of 20 min makes this method well suited for emergency cases. Precision and accuracy of the method are presented. Results are not biased by interferences, not even from N-acetylcysteine.

Application of Diode Lasers in Interferometrical Length Measurements

2010 ◽  
Vol 437 ◽  
pp. 423-427 ◽  
Author(s):  
Alexander Höink ◽  
Karl Meiners-Hagen ◽  
Otto Jusko ◽  
Ahmed Abou-Zeid
Keyword(s):  
Diode Laser ◽  
Diode Lasers ◽  
Experimental Results ◽  
Length Measurements ◽  
Multi Wavelength ◽  
Different Diameters ◽  
Laser Interferometers

The experimental results for the determination of the form of thin cylinders (Ø ~ 2.5 mm) as well as step heights of gauge blocks (~ 100 µm) and roundness profiles of test samples from metal or glass with different diameters between ~ 2.5 mm and 80 mm using two multi-wavelength diode laser interferometers are presented and discussed.

scholarly journals Two-wavelength thermal–optical determination of light-absorbing carbon in atmospheric aerosols

2019 ◽  
Vol 12 (6) ◽  
pp. 3173-3182 ◽  
Author(s):  
Dario Massabò ◽  
Alessandro Altomari ◽  
Virginia Vernocchi ◽  
Paolo Prati
Keyword(s):  
Laser Diode ◽  
Atmospheric Aerosols ◽  
Direct Determination ◽  
Optical Transmittance ◽  
Carbonaceous Aerosol ◽  
Electromagnetic Spectrum ◽  
Multi Wavelength ◽  
Physics Department ◽  
The University

Abstract. Thermal–optical analysis is widely adopted for the quantitative determination of total (TC), organic (OC), and elemental (EC) carbon in atmospheric aerosol sampled by suitable filters. Nevertheless, the methodology suffers from several uncertainties and artifacts such as the well-known issue of charring affecting the OC–EC separation. In the standard approach, the effect of the possible presence of brown carbon, BrC, in the sample is neglected. BrC is a fraction of OC, usually produced by biomass burning with a thermic behavior intermediate between OC and EC. BrC is optically active: it shows an increasing absorbance when the wavelength moves to the blue–UV region of the electromagnetic spectrum. Definitively, the thermal–optical characterization of carbonaceous aerosol should be reconsidered to address the possible BrC content in the sample under analysis. We introduce here a modified Sunset Lab Inc. EC–OC analyzer. Starting from a standard commercial instrument, the unit has been modified at the physics department of the University of Genoa (Italy), making possible the alternative use of the standard laser diode at λ=635 nm and of a new laser diode at λ=405 nm. In this way, the optical transmittance through the sample can be monitored at both wavelengths. Since at shorter wavelengths the BrC absorbance is higher, a better sensitivity to this species is gained. The modified instrument also gives the possibility to quantify the BrC concentration in the sample at both wavelengths. The new unit has been thoroughly tested, with both artificial and real-world aerosol samples: the first experiment, in conjunction with the multi-wavelength absorbance analyzer (MWAA; Massabò et al., 2013, 2015), resulted in the first direct determination of the BrC mass absorption coefficient (MAC) at λ=405 nm: MAC =23±1 m2 g−1.

scholarly journals A multi-channel photometric detector for multi-component analysis in flow injection analysis

1994 ◽  
Vol 16 (2) ◽  
pp. 71-73 ◽  
Author(s):  
Aimin Tan ◽  
Jialin Huang ◽  
Liudi Geng ◽  
Jinhua Xu ◽  
Xinna Zhao
Keyword(s):  
Zinc Sulphate ◽  
Light Emitting Diode ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Light Emitting ◽  
Flow Cells ◽  
Photometric Detector ◽  
Sulphate Electrolyte ◽  
Multi Wavelength

The detector, a multi-channel photometric detector, described in this paper was developed using multi-wavelength LEDs (light emitting diode) and phototransistors for absorbance measurement controlled by an Intel 8031 8-bit single chip microcomputer. Up to four flow cells can be attached to the detector. The LEDs and phototransistors are both inexpensive, and reliable. The results given by the detector for simultaneous determination of trace amounts of cobalt and cadmium in zinc sulphate electrolyte are reported. Because of the newly developed detector, this approach employs much less hardware apparatus than by employing conventional photometric detectors.

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