scholarly journals H2O Collisional Broadening Coefficients at 1.37 µm and Their Temperature Dependence: A Metrology Approach

2021 ◽  
Vol 11 (12) ◽  
pp. 5341
Author(s):  
Javis A. Nwaboh ◽  
Olav Werhahn ◽  
Volker Ebert
Keyword(s):  
International System ◽  
The Self ◽  
Uncertainty In Measurement ◽  
Collisional Broadening ◽  
Temperature Coefficients ◽  
System Of Units ◽  
Laser Spectroscopic ◽  
Expression Of Uncertainty ◽  
Measurement Approach ◽  
Good Agreement

We report self- and air collisional broadening coefficients for the H2O line at 7299.43 cm−1 and corresponding temperature coefficients for a temperature range spanning 293–573 K. New laser spectroscopic setups specifically designed for this purpose have been developed and are described. The line parameters reported here are in good agreement with those values reported in the HITRAN 2020 database, but the uncertainties have been reduced by factors of about 4, 1.3 and 4.4 for the self-broadening coefficient, air broadening coefficient and the temperature exponent of air broadening, respectively. Further, we combined our measurement approach with metrological data quality objectives, addressing the traceability of the results to the international system of units (SI) and evaluated the uncertainties following the guide to the expression of uncertainty in measurement (GUM).

scholarly journals The geomagnetic data of the Clementinum observatory in Prague since 1839

2021 ◽  
Author(s):  
Pavel Hejda ◽  
Fridrich Valach ◽  
Miloš Revallo
Keyword(s):  
Missing Values ◽  
International System ◽  
Magnetic Observatory ◽  
Historical Source ◽  
Historical Sources ◽  
Temperature Coefficients ◽  
System Of Units ◽  
Geomagnetic Data ◽  
Absolute Measurements

Abstract. The historical magnetic observatory Clementinum operated in Prague from 1839 to 1926. The data from the yearbooks that recorded the observations at Clementinum have recently been digitized and were subsequently converted in this work into the physical units of the International System of Units (SI). Introducing a database of geomagnetic data from this historical source is a part of our paper. Some controversial data are also analysed here. In the original historical sources, we identified an error in using the physical units. It was probably introduced by the then observers with the determination of the temperature coefficient of the bifilar apparatus. By recalculating the values ​​in the records, some missing values ​​are added; for instance, the temperature coefficients for the bifilar magnetometer, the baselines, and the annual averages for the horizontal intensity in the first years of observations were re-determined. The values ​​of absolute measurements of the declination in 1852, which could not be found in the original sources, were also estimated. The main contribution of this article rests in critically reviewed information about the magnetic observations in Prague, which is as complete as no other so far. The work also contributes to the space weather topic by revealing a record of the now almost forgotten magnetic disturbance of 3 September 1839.

Monte Carlo Analysis as a Tool for Characterizing Uncertainty in Optical Calibration of End Standards

2010 ◽  
Vol 3 ◽  
pp. 18-27
Author(s):  
Niveen Farid
Keyword(s):  
Monte Carlo ◽  
Statistical Analysis ◽  
Conventional Method ◽  
Monte Carlo Analysis ◽  
Uncertainty In Measurement ◽  
M 10 ◽  
Optical Calibration ◽  
Expression Of Uncertainty ◽  
Probability Density Function Pdf ◽  
Good Agreement

In this paper, Monte Carlo method (MCM) is used to analyze the uncertainty of optical calibration of end standards using both contact and non-contact techniques to validate the uncertainty values obtained by the conventional method, Guide to the expression of Uncertainty in Measurement (GUM). Number of trials (M=104) is simulated with the probability density function (pdf) for each quantity, and the comparison between the results of the MCM and the GUM shows good agreement which in turn validates the uncertainty values obtained by the conventional method. The statistical analysis, variables' distributions, and the output of each technique are discussed in detail.

scholarly journals High accuracy AC current sources calibration by single junction thermal converters at INM

DYNA ◽  
2021 ◽  
Vol 88 (216) ◽  
pp. 117-125
Author(s):  
Carlos Fernando Hernández Prada ◽  
Mauricio Sáchica Avellaneda ◽  
Alexander Martínez lópez
Keyword(s):  
International System ◽  
Measurement Model ◽  
Uncertainty Budget ◽  
High Accuracy ◽  
Effect Of Temperature ◽  
National Metrology Institute ◽  
Single Junction ◽  
Uncertainty In Measurement ◽  
System Of Units ◽  
Ac Current

The National Metrology Institute of Colombia (INM) uses high accuracy calibrators (such as Fluke 5720A/5730A) as AC current reference standards. We describe the implementation at INM of AC-DC current transfer standards by single junction thermal converters (SJTC) to improve the accuracy of AC measurements and give traceability to the International System of Units (SI) within the country. We describe the measurement model, present the uncertainty budget estimation accordingly to the Guide to the Expression of Uncertainty in Measurement (GUM) and analyze the effect of temperature and electrostatic on measurements. Expanded uncertainties between 68 μA/A and 2.6 mA/A were obtained for the calibration of high accuracy calibrators and transconductance amplifiers for currents from 5 mA to 20 A (40 Hz to 5 kHz). The obtained measurement results are compatible with calibration results from the National Metrology Institutes like Centro Nacional de Metrología from Mexico (CENAM) and Accredited International Laboratories like Fluke.

scholarly journals A Precise Gas Dilutor Based on Binary Weighted Critical Flows to Create NO2 Concentrations

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 998 ◽  
Author(s):  
Philipp Breitegger ◽  
Alexander Bergmann
Keyword(s):  
Reference Method ◽  
Dilution Ratio ◽  
Total Flow ◽  
Uncertainty In Measurement ◽  
Gas Cylinder ◽  
Extended Uncertainty ◽  
Binary Weighted ◽  
Chemiluminescence Detector ◽  
Expression Of Uncertainty ◽  
Good Agreement

A gas diluter based on critical orifices was built and evaluated. The gas diluter is capable of creating dilution ratios of 1:1400 at a total flow of 6.5 L/min. An extended uncertainty analysis of gas concentrations and dilution ratios according to the Guide to the Expression of Uncertainty in Measurement was conducted. A gas cylinder of 5.16 ppm NO2 with a relative uncertainty of 1.5% (k = 1) can be diluted down to a concentration of 3.69 ppb NO2 (dilution ratio of 1:1400) at an uncertainty of 1.9% (k = 1). The results are in good agreement with reference NO2 measurements, conducted with a chemiluminescence detector (CLD, European reference method EN14211; 2005).

scholarly journals The geomagnetic data of the Clementinum observatory in Prague since 1839

2021 ◽  
Vol 39 (3) ◽  
pp. 439-454
Author(s):  
Pavel Hejda ◽  
Fridrich Valach ◽  
Miloš Revallo
Keyword(s):  
Missing Values ◽  
International System ◽  
Magnetic Observatory ◽  
Magnetic Disturbance ◽  
Historical Source ◽  
Historical Sources ◽  
Temperature Coefficients ◽  
System Of Units ◽  
Geomagnetic Data ◽  
Absolute Measurements

Abstract. The historical magnetic observatory Clementinum operated in Prague from 1839 to 1926. The data from the yearbooks that recorded the observations at Clementinum have recently been digitized and were subsequently converted, in this work, into the physical units of the International System of Units (SI). Introducing a database of geomagnetic data from this historical source is a part of our paper. Some controversial data are also analysed here. In the original historical sources, we identified an error in using the physical units. It was probably introduced by the observers determining the temperature coefficient of the bifilar apparatus. By recalculating the values ​​in the records, some missing values ​​are added; for instance, the temperature coefficients for the bifilar magnetometer, the baselines, and the annual averages for the horizontal intensity in the first years of observations were redetermined. The values ​​of absolute measurements of the declination in 1852, which could not be found in the original sources, were also estimated. The main contribution of this article rests in critically reviewed information about the magnetic observations in Prague, which is, so far, more complete than any other. The work also contributes to the space weather topic by revealing a record of the now almost forgotten magnetic disturbance of 3 September 1839.

Dimensions of plane and solid angles and their units in the International System of Units (SI)

2020 ◽  
pp. 26-32
Author(s):  
M. I. Kalinin ◽  
L. K. Isaev ◽  
F. V. Bulygin
Keyword(s):  
Solid Angle ◽  
International System ◽  
International Committee ◽  
Plane Angle ◽  
Arc Length ◽  
Weights And Measures ◽  
International System Of Units ◽  
System Of Units ◽  
In Series ◽  
Solid Angles

The situation that has developed in the International System of Units (SI) as a result of adopting the recommendation of the International Committee of Weights and Measures (CIPM) in 1980, which proposed to consider plane and solid angles as dimensionless derived quantities, is analyzed. It is shown that the basis for such a solution was a misunderstanding of the mathematical formula relating the arc length of a circle with its radius and corresponding central angle, as well as of the expansions of trigonometric functions in series. From the analysis presented in the article, it follows that a plane angle does not depend on any of the SI quantities and should be assigned to the base quantities, and its unit, the radian, should be added to the base SI units. A solid angle, in this case, turns out to be a derived quantity of a plane angle. Its unit, the steradian, is a coherent derived unit equal to the square radian.

Verification of the Calculation Assumptions Applied to Solutions of the Acoustic Measurements Uncertainty

2015 ◽  
Vol 39 (2) ◽  
pp. 199-202
Author(s):  
Wojciech Batko ◽  
Renata Bal
Keyword(s):  
Normal Distribution ◽  
Confidence Intervals ◽  
Uncertainty Of Measurement ◽  
Acoustic Measurements ◽  
Uncertainty In Measurement ◽  
Sound Levels ◽  
Measurement Results ◽  
Analysis Of Results ◽  
Essential Problem ◽  
Expression Of Uncertainty

Abstract The assessment of the uncertainty of measurement results, an essential problem in environmental acoustic investigations, is undertaken in the paper. An attention is drawn to the - usually omitted - problem of the verification of assumptions related to using the classic methods of the confidence intervals estimation, for the controlled measuring quantity. Especially the paper directs attention to the need of the verification of the assumption of the normal distribution of the measuring quantity set, being the base for the existing and binding procedures of the acoustic measurements assessment uncertainty. The essence of the undertaken problem concerns the binding legal and standard acts related to acoustic measurements and recommended in: 'Guide to the expression of uncertainty in measurement' (GUM) (OIML 1993), developed under the aegis of the International Bureau of Measures (BIPM). The model legitimacy of the hypothesis of the normal distribution of the measuring quantity set in acoustic measurements is discussed and supplemented by testing its likelihood on the environment acoustic results. The Jarque-Bery test based on skewness and flattening (curtosis) distribution measures was used for the analysis of results verifying the assumption. This test allows for the simultaneous analysis of the deviation from the normal distribution caused both by its skewness and flattening. The performed experiments concerned analyses of the distribution of sound levels: LD, LE, LN, LDWN, being the basic noise indicators in assessments of the environment acoustic hazards.

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