The fractal calibration method applied to the characterization of polymers in solvent mixtures and in mixed gel packings by SEC

2007 ◽  
Vol 30 (13) ◽  
pp. 2037-2045 ◽  
Author(s):  
Iolanda Porcar ◽  
Rosa García-Lopera ◽  
Concepción Abad ◽  
Agustín Campos
Keyword(s):  
Calibration Method ◽  
Solvent Mixtures

Characterization of ternary solvent mixtures: the methanol/ethanol/acetone mixture

2003 ◽  
Vol 371 (5-6) ◽  
pp. 645-654 ◽  
Author(s):  
C Dı́az ◽  
L Barrio ◽  
J Catalán
Keyword(s):  
Solvent Mixtures

scholarly journals Technical note: Characterization of a static thermal-gradient CCN counter

2006 ◽  
Vol 6 (2) ◽  
pp. 2151-2174 ◽  
Author(s):  
G. P. Frank ◽  
U. Dusek ◽  
M. O. Andreae
Keyword(s):  
Water Vapor ◽  
Thermal Gradient ◽  
Cloud Condensation Nuclei ◽  
Diffusion Chamber ◽  
Calibration Method ◽  
Theoretical Description ◽  
Technical Note ◽  
Number Concentration ◽  
Gradient Diffusion

Abstract. The static (parallel-plate thermal-gradient) diffusion chamber (SDC) was one of the first instruments designed to measure cloud condensation nuclei (CCN) concentrations as a function of supersaturation. It has probably also been the most widely used type of CCN counter. This paper describes the detailed experimental characterization of a SDC CCN counter, including calibration with respect to supersaturation and particle number concentration. In addition, we investigated the proposed effect of lowered supersaturation because of water vapor depletion with increasing particle concentration. The results obtained gives a larger understanding why and in which way it is necessary to calibrate the SDC CCN counter. The calibration method is described in detail as well. The method can, in parts, be used for calibrations also for other types of CCN counters. We conclude the following: 1) it is important to experimentally calibrate SDC CCN counters with respect to supersaturation, and not only base the supersaturation on the theoretical description of the instrument; 2) the number concentration calibration needs to be performed as a function of supersaturation, also for SDC CCN counter using the photographic technique; and 3) we observed no evidence that water vapor depletion lowered the supersaturation.

Sectorial substrate-integrated half-mode near-field sensors for biological liquid characterization

2014 ◽  
Vol 6 (3-4) ◽  
pp. 305-312 ◽  
Author(s):  
Nora Meyne ◽  
Arne F. Jacob
Keyword(s):  
Factor Analysis ◽  
Perturbation Theory ◽  
Aqueous Solutions ◽  
Quality Factor ◽  
Near Field ◽  
Calibration Method ◽  
Biological Liquid ◽  
Suitable Reference ◽  
5 Ghz

Two compact resonant near-field sensors are introduced for the characterization of aqueous solutions at 5 GHz. They are based on folded substrate-integrate circular half-mode resonators with a planar sensing tip. Owing to the planar design, the sensor is simple and cheap to manufacture, and a sample can be easily coupled to the resonator from the top. The operating principle of the sensor is explained and verified by both simulation and measurement. The radiation of the sensors is quantified by means of a quality factor analysis. Finally, a previously introduced calibration method based on the perturbation theory is applied to the sensors and its accuracy is improved by choosing more suitable reference materials.

scholarly journals Measurements on pointing error and field of view of Cimel-318 Sun photometers in the scope of AERONET-Europe

2013 ◽  
Vol 6 (2) ◽  
pp. 3013-3057
Author(s):  
B. Torres ◽  
C. Toledano ◽  
A. Berjón ◽  
D. Fuertes ◽  
V. Molina ◽  
...  
Keyword(s):  
Calibration Method ◽  
Field Of View ◽  
Pointing Error ◽  
Vicarious Calibration ◽  
Movement Correction ◽  
Measurement Protocol ◽  
The Matrix ◽  
First Results ◽  
Sensitivity Studies

Abstract. Sensitivity studies indicate that among the different error sources of ground-based sky radiometer observations, the pointing error has an important role in the correct retrieving of aerosol properties, being specially critical for the characterization of desert dust aerosol. The present work analyzes the first results of two new measurements, cross and matrix, specifically designed for an evaluation of the pointing error in the standard instrument of the Aerosol Robotic Network, the Cimel CE-318 sun-photometer. The first part of the analysis contains a preliminary study whose results conclude on the need of a sun movement correction for the correct evaluation of the pointing error from both new measurements. Once this correction is applied, both measurements show an equivalent behavior with differences under 0.01° in the evaluation of the pointing error. The second part of the analysis includes the incorporation of the cross scenario in the AERONET routine measurement protocol in order to monitor the pointing error in field instruments. Using the data collected for more than a year, the pointing error is evaluated on 7 sun-photometers belonging to AERONET-Europe. The pointing error values registered are generally smaller than 0.01° though in some instruments values up to 0.03° have been observed. Moreover, the pointing error evaluation has shown that this measure can be used to detect mechanical problems in the robots or dirtiness in the quadrant detector due to the stable behavior of the values against time and solar zenith angle. At the same time, the matrix scenario can be used to derive the value of the field of view. The methodology implemented and the characterization of five sun-photometers is presented in the last part of the study. To validate the method, a comparison with field of view values obtained from the vicarious calibration method was developed. The differences between both techniques are under 3%.

scholarly journals Measurements on pointing error and field of view of Cimel-318 Sun photometers in the scope of AERONET

2013 ◽  
Vol 6 (8) ◽  
pp. 2207-2220 ◽  
Author(s):  
B. Torres ◽  
C. Toledano ◽  
A. Berjón ◽  
D. Fuertes ◽  
V. Molina ◽  
...  
Keyword(s):  
Calibration Method ◽  
Pointing Error ◽  
Vicarious Calibration ◽  
Movement Correction ◽  
Measurement Protocol ◽  
The Matrix ◽  
Mechanical Faults ◽  
Sensitivity Studies ◽  
Error Estimations

Abstract. Sensitivity studies indicate that among the diverse error sources of ground-based sky radiometer observations, the pointing error plays an important role in the correct retrieval of aerosol properties. The accurate pointing is specially critical for the characterization of desert dust aerosol. The present work relies on the analysis of two new measurement procedures (cross and matrix) specifically designed for the evaluation of the pointing error in the standard instrument of the Aerosol Robotic Network (AERONET), the Cimel CE-318 Sun photometer. The first part of the analysis contains a preliminary study whose results conclude on the need of a Sun movement correction for an accurate evaluation of the pointing error from both new measurements. Once this correction is applied, both measurements show equivalent results with differences under 0.01° in the pointing error estimations. The second part of the analysis includes the incorporation of the cross procedure in the AERONET routine measurement protocol in order to monitor the pointing error in field instruments. The pointing error was evaluated using the data collected for more than a year, in 7 Sun photometers belonging to AERONET sites. The registered pointing error values were generally smaller than 0.1°, though in some instruments values up to 0.3° have been observed. Moreover, the pointing error analysis shows that this measurement can be useful to detect mechanical problems in the robots or dirtiness in the 4-quadrant detector used to track the Sun. Specifically, these mechanical faults can be detected due to the stable behavior of the values over time and vs. the solar zenith angle. Finally, the matrix procedure can be used to derive the value of the solid view angle of the instruments. The methodology has been implemented and applied for the characterization of 5 Sun photometers. To validate the method, a comparison with solid angles obtained from the vicarious calibration method was developed. The differences between both techniques are below 3%.

Characterization of a high‐frequency pressure‐field calibration method.

2010 ◽  
Vol 127 (3) ◽  
pp. 1980-1980 ◽  
Author(s):  
Dylan Alexander ◽  
Casey Barnard ◽  
Benjamin A. Griffin ◽  
Mark Sheplak
Keyword(s):  
High Frequency ◽  
Pressure Field ◽  
Calibration Method ◽  
Field Calibration

Characterization of Alcohol Solvents by the Empirical Polarity Parameters AN, Z, and ET(30)

1982 ◽  
Vol 37 (6) ◽  
pp. 684-687 ◽  
Author(s):  
Horst Elias ◽  
Michael Dreher ◽  
Sabine Neitzel ◽  
Harald Volz
Keyword(s):  
Benzyl Alcohol ◽  
Solvent Effects ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Acceptor Number ◽  
Binary Solvent Mixtures ◽  
Alcohol Solvents ◽  
Polarity Parameters

AbstractThe acceptor number AN and the polarity parameters Z and ET(30) were determined for a series of alcohols applied as media in the study of kinetic solvent effects. The alcohols thus characterized are methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, 2-methyl-2-butanol, 3-pentanol, 2-chloroethanol, 2-methoxyethanol, 2-phenylethanol, 2-cyanoethanol, benzyl alcohol, 3-ethyl-3-pentanol, 2,4-dimethyl-3-pentanol, and 3-ethyl-2,4-dimetliyl-3-pentanol. In addition, AN was determined for 1,2-dichloroethane and Z for the binary solvent mixtures methanol/2-methyl-2-butanol, ethanol/2,2,2-trifluoroethanol. and methanol/pyridine. The data obtained are correlated and the parameters AN, Z, and ET(30) are critically compared.

scholarly journals Influence of the calibration on experimental UV index at a midlatitude site, Granada (Spain)

2010 ◽  
Vol 3 (6) ◽  
pp. 5645-5670
Author(s):  
M. Antón ◽  
J. E. Gil ◽  
A. Cazorla ◽  
J. M. Vilaplana ◽  
F. J. Olmo ◽  
...  
Keyword(s):  
Calibration Method ◽  
Conversion Factors ◽  
Uv Index ◽  
Calibration Methods ◽  
One Step ◽  
The Difference ◽  
Mean Differences ◽  
Experimental Values ◽  
The One

Abstract. The ultraviolet (UV) index is the variable most commonly used to inform the general public about the levels and potential harmful effects of UV radiation incident at Earth's surface. This variable is derived from the output signal of the UV radiometers applying conversion factors obtained by calibration methods. This paper focused on the influence of the use of two of these methods (called one-step and two-steps methods) on the resulting experimental UV Index (UVI) as measured by a YES UVB-1 radiometer located in a midlatitude station, Granada (Spain) for the period 2006–2009. In addition, it is also analyzed the difference with the UVI values obtained when the calibration factors provided by the manufacturer are used. For this goal, the detailed characterization of the UVB-1 radiometer obtained in the first Spanish calibration campaign of broadband UV radiometers at the "El Arenosillo" INTA station in 2007 is used. In addition, modeled UVI data derived from the LibRadtran/UVSPEC radiative transfer code are compared with the experimental values recorded at Granada for cloud-free conditions. The absolute mean differences between the measured and modeled UVI data at Granada are around 5% using the one-step and two-steps calibration methods. This result indicates the excellent performance of these two techniques for obtaining UVI data from the UVB-1 radiometer. In contrast, the application of the calibration factor supplied by the manufacturer produces a high overestimation (~14%) of the UVI values. This fact generates unreliable alarming high UVI data in summer when the manufacturer's factor is used. Thus, days with an extreme erythemal risk (UVI higher than 10) increase up to 46% of all cases measured between May and September at Granada when the manufacturer's factor is applied. This percentage is reduced to a more reliable value of 3% when the conversion factors obtained with the two-steps calibration method are used. All these results report about the need of a sound calibration of the broadband UV instruments in order to obtain reliable measurements.

Sign in / Sign up

Export Citation Format

Share Document