uncertainty component
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Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4013
Author(s):  
Krzysztof Dziarski ◽  
Arkadiusz Hulewicz ◽  
Grzegorz Dombek

The number of components of a thermographic temperature measurement uncertainty budget and their ultimate contribution depend on the conditions in which the measurement is performed. The acquired data determine the accuracy with which the uncertainty component is estimated. Unfortunately, when some factors have to be taken into account, it is difficult to determine the value of the uncertainty component caused by the occurrence of this factor. In the case of a thermographic temperature measurement, such a factor is the lack of sharpness of the registered thermogram. This problem intensifies when an additional macro lens must be used. Therefore, it is decided to commence research to prepare an uncertainty budget of thermographic measurement with an additional macro lens based on the B method described in EA-4/02 (European Accreditation publications). As a result, the contribution of factors in the uncertainty budget of thermographic measurement with additional macro lens and the value of expanded uncertainty were obtained.


2021 ◽  
Vol 13 (1) ◽  
pp. 40-45
Author(s):  
Elsa Batista ◽  
Isabel Godinho ◽  
George Rodrigues ◽  
Doreen Rumery

There are two methods generally used for calibration of micropipettes: the gravimetric method described in ISO 8655-6:2002 and the photometric method described in ISO 8655-7:2005. In order to validate the photometric method, several micropipettes of different capacities from 0.1 µL to 1000 µL were calibrated using both methods (gravimetric and photometric) in two different laboratories, IPQ (Portuguese Institute for Quality) and Artel. These tests were performed by six different operators. The uncertainty for both methods was determined and it was verified that the uncertainty component that has a higher contribution to the final uncertainty budget depends on the volume delivered. In the photometric method for small volumes, the repeatability of the pipette is the largest uncertainty component, but for volumes, larger than 100 µL, the photometric instrument is the most significant source of uncertainty. Based on all the results obtained with this study, one may consider the photometric method validated.


2021 ◽  
Vol 267 ◽  
pp. 02039
Author(s):  
Yan Rong ◽  
Linyuan Guo ◽  
Yunyan Peng ◽  
Jianhua Yang ◽  
Dong Jin

The closed flash point is an important indicator in the detection of organic heat carrier. In this paper, based on the Pensky-Martin flash point (closed) measurement method, the closed flash point of the organic heat carrier is measured with an automatic closed cup flash point meter. The factors that may affect the accuracy of the measurement result during the measurement process are analyzed, and the uncertainty is determined. Through the analysis of the established uncertainty component sources, the repeatability measurement of the organic heat carrier, the temperature sensor, the pressure sensor, and the numerical rounding based on the standard, the results of the closed flash point determination of the organic heat carrier are obtained. The synthetic uncertainty and the relative expanded uncertainty are evaluated to improve the reliability of the measurement results of the closed flash point of the organic heat carrier and provide a reference for the quality control of the organic heat carrier.


2019 ◽  
Vol 21 (3) ◽  
pp. 171
Author(s):  
Hayati Amalia ◽  
Agah Faisal

<p>This paper presents a traceable measurement method developed in the Laboratory of National Measurement Standards for Electricity and Time (NMS Lab for Electricity and Time) - National Standardization Agency of Indonesia for calibrating current coil in order to obtain correction and uncertainty estimation of the current coil windings number (N). Current coils as objects of this research were 10-turn and 50-turn current coil. Calibration was performed using standard multiproduct calibrator (MPC) and two auxiliary devices, current coil F-5500 and clamp meter F-337. Correction and uncertainty values of N current coil were evaluated for DC and AC supplied current using formulation developed based on principle of current division between current coil output and supplied current from MPC. Based on evaluation result analysis, the expanded uncertainties of this method span from 0.47% to 1.0% (when supplied by DC current) and from 0.57% to 1.1% (when supplied by AC current) for 10-turn current coil, and span from 0.44% to 0.65% (when supplied by DC current) and from 0.54% to 0.96% (when supplied by AC current) for 50-turn current coil. Moreover, it also showed that the largest uncertainty component came from current coil F-5500. Meanwhile, the largest correction for 10-turn current coil was obtained 1.2% at 10 A DC, and for 50-turn current coil was obtained -0.47% at 700 A AC. Verification of the calibration and evaluation methods had also been carried out and it indicated that the calibration and analysis methods developed can be used to examine the performance of the current coil.</p>


Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4343 ◽  
Author(s):  
Giechaskiel ◽  
Zardini ◽  
Lähde ◽  
Clairotte ◽  
Forloni ◽  
...  

The recent Euro 4 and 5 environmental steps for L-category vehicles (e.g., mopeds, motorcycles) were mainly designed to reduce the emissions of particulate matter and ozone precursors, such as nitrogen oxides and hydrocarbons. However, the corresponding engine, combustion, and aftertreatment improvements will not necessarily reduce the solid particle number (SPN) emissions, suggesting that a SPN regulation may be necessary in the future. At the same time, there are concerns whether the current SPN regulations of passenger cars can be transferred to L-category vehicles. In this study we quantified the errors and uncertainties in emission measurements, focusing on SPN. We summarized the sources of uncertainty related to emission measurements and experimentally quantified the contribution of each uncertainty component to the final results. For this reason, gas analyzers and SPN instruments with lower cut-off sizes of 4 nm, 10 nm, and 23 nm were sampling both from the tailpipe, and from the dilution tunnel having the transfer tube in closed or open configuration (i.e., open at the tailpipe side). The results showed that extracting from the tailpipe 23–28% of the mean total exhaust flow (bleed off) resulted in a 24–31% (for CO2) and 19–73% (for SPN) underestimation of the emissions measured at the dilution tunnel. Erroneous determination of the exhaust flow rate, especially at cold start, resulted in 2% (for CO2) and 69–149% (for SPN) underestimation of the tailpipe emissions. Additionally, for SPN, particle losses in the transfer tube with the closed configuration decreased the SPN concentrations around 30%, mainly due to agglomeration at cold start. The main conclusion of this study is that the open configuration (or mixing tee) without any instruments measuring from the tailpipe is associated with better accuracy for mopeds, especially related to SPN measurements. In addition, we demonstrated that for this moped the particle emissions below 23 nm, the lower size currently prescribed in the passenger cars regulation, were as high as those above 23 nm; thus, a lower cut-off size is more appropriate.


2019 ◽  
Vol 53 (5-6) ◽  
pp. 2501-2516 ◽  
Author(s):  
Benoit Hingray ◽  
Juliette Blanchet ◽  
Guillaume Evin ◽  
Jean-Philippe Vidal

Author(s):  
Yuriy Kostyuchenko ◽  
Anna Kozlova ◽  
Dmytro Movchan ◽  
Olga Sedlerova ◽  
Maxim Yuschenko

The problem of uncertainty analysis in complex multi-component systems is considered. The problem of decision making with uncertainty in tasks modeling carbon balance and the analysis of greenhouse gas (GHG) emissions using satellite tools was considered. Approaches to decision making under uncertainty are described in terms of interval, fuzzy, and stochastic assessments. Different approaches and algorithms to calculate carbon and GHG emissions are described. For every algorithm, errors and uncertainties are analyzed and estimated. Algorithms for uncertainty analysis based on integrated interlinked models of the system are presented. Algorithms for the analysis of components of vegetation productivity assessment using satellite data are proposed. Uncertainty component analysis allows the understanding of important properties of the system studied, and its feedback as to its anthropogenic load and impact on the climate. It was demonstrated that the comprehensive analysis of uncertainties allows not only the reduction of errors, but new knowledge about the studied systems.


ACTA IMEKO ◽  
2017 ◽  
Vol 6 (4) ◽  
pp. 95
Author(s):  
Christian Müller-Schöll

<p>For the calibration of weight pieces, the evaluation of comparator sensitivity and its associated uncertainty component is essential.<br />Yet, there is not much documented guidance on how to assess these values. This paper proposes a procedure for assessing, evaluating<br />and optimizing mass comparator sensitivity.</p>


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