scholarly journals Modeling Measurement Uncertainty in Room Acoustics

10.14311/972 ◽  
2007 ◽  
Vol 47 (4-5) ◽  
Author(s):  
P. Dietrich
Keyword(s):  
Measurement Errors ◽  
Influence Factors ◽  
Uncertainty Budget ◽  
Room Acoustics ◽  
Acoustic Parameters ◽  
Uncertainty In Measurement ◽  
Measurement Results ◽  
Combined Uncertainty ◽  
Main Influence

This paper investigates a way of determining and modeling uncertainty contributions in measurements of room acoustic parameters, which are commonly used to describe the acoustic situation of a room in an objective manner. If the range of uncertainty and the confidence interval are not given, the results remain incomparable to other measurement teams, since modern PC-based measurements still show appreciable sources of measurement errors. The Guide to the Expression of Uncertainty in Measurement (GUM) defines a unified guideline for determining uncertainties in all fields of measurement. Its application is increasingly required by modern measurement standards. However, the GUM procedures have not been applied to room acoustics yet. Hence, a scalable linear approach for calculating the combined uncertainty of room acoustic parameters with regard to the input quantities is proposed. In-situ measurement results of specially designed experiments show the significance of the main influence factors and are used to build the uncertainty budget. 

Uncertainty Analysis of Helical Deviation Measurements

2010 ◽  
Vol 437 ◽  
pp. 212-216 ◽  
Author(s):  
Zhao Yao Shi ◽  
Jia Chun Lin ◽  
Michael Paul Krystek
Keyword(s):  
Measurement Uncertainty ◽  
Measurement Errors ◽  
National Standards ◽  
Calculation Procedure ◽  
Uncertainty In Measurement ◽  
Uncertainty Calculation ◽  
Measurement Results ◽  
Polar Coordinate ◽  
Expression Of Uncertainty ◽  
Dynamical Measurement

The helix is a complex geometrical element. During the process of a dynamical measurement of the helical deviations, many factors, including the machine and the environment, lead to measurement errors. Although ISO as well as national standards stipulate the tolerances and assessment methods for helical deviations, these standards contribute little to the uncertainty calculations concerning such measurements. According to the Guide to the Expression of Uncertainty in Measurement (GUM), all measurement results must have a stated uncertainty associated to them. But in most cases of helical deviation measurements, no uncertainty value is given, simply because no measurement uncertainty calculation procedure exists. For the case of helical deviation measurements on a Computer Numeric Control (CNC) polar coordinate machine, this paper analyses in detail all kinds of factors contributing to the measurement uncertainty, and gives the calculation procedure of the measurement uncertainty of helical deviation. As an example, the calculation of the measurement uncertainty of the helical deviations of a worm is presented.

Development of reference materials with the composition of propyl and isopropyl alcohol solutions

2020 ◽  
pp. 66-72
Author(s):  
Irina A. Piterskikh ◽  
Svetlana V. Vikhrova ◽  
Nina G. Kovaleva ◽  
Tatyana O. Barynskaya
Keyword(s):  
Reference Materials ◽  
Measurement Errors ◽  
Isopropyl Alcohol ◽  
Certified Reference Materials ◽  
Toxic Substances ◽  
Biological Objects ◽  
Margin Of Error ◽  
Measurement Results ◽  
And Control ◽  
Characteristic Mass

Certified reference materials (CRM) composed of propyl (11383-2019) and isopropyl (11384-2019) alcohols solutions were created for validation of measurement procedures and control of measurement errors of measurement results of mass concentrations of toxic substances (alcohol) in biological objects (urine, blood) and water. Two ways of establishing the value of the certified characteristic – mass consentration of propanol-1 or propanol-2 have been studied. The results obtained by the preparation procedure and comparison with the standard are the same within the margin of error.

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.

scholarly journals Evolution of Internal Stress in Heterogeneous Electrode Composite during the Drying Process

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1683
Author(s):  
Zuoquan Zhu ◽  
Yaolong He ◽  
Hongjiu Hu ◽  
Fangzhou Zhang
Keyword(s):  
Internal Stress ◽  
Vinylidene Fluoride ◽  
Influence Factors ◽  
Lithium Ion ◽  
Integrated Analysis ◽  
Drying Time ◽  
Component Distribution ◽  
Poly Vinylidene Fluoride ◽  
Inactive Ingredients ◽  
Main Influence

The mechanical behavior of electrode composite during the drying preparation has played a crucial role in the electrochemical performance of lithium-ion batteries (LIBs). Our work aimed at developing an integrated analysis method to study the component distribution, mechanical properties, and internal stress of composite coating in the process of electrode drying. The main influence factors of drying stress were thoroughly investigated. It was found that this present model could capture not only the heterogeneity effect of inactive ingredients but also the porosity-dependent viscoelasticity of electrode composite. Meanwhile, the calculated effective modulus and stress evolution upon drying time were in acceptable accord with the experimental data. Furthermore, the rapid solidification markedly increased the drying stress in electrodes and significantly impaired the tensile strength of electrode composite due to the highly gradient distributed constituents. However, the stress level at high drying temperature could be significantly reduced by an aqueous sodium alginate binder instead of poly(vinylidene fluoride). The obtained results will be a great help in efficiently manufacturing LIB electrodes with adequate mechanical integrity.

scholarly journals Progress in Traceable Nanoscale Capacitance Measurements Using Scanning Microwave Microscopy

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 820
Author(s):  
François Piquemal ◽  
José Morán-Meza ◽  
Alexandra Delvallée ◽  
Damien Richert ◽  
Khaled Kaja
Keyword(s):  
Uncertainty Budget ◽  
Dielectric Constants ◽  
Electrical Measurements ◽  
Capacitance Measurements ◽  
Uncertainty Sources ◽  
Microwave Microscopy ◽  
Calibration Methods ◽  
Combined Uncertainty ◽  
Calibration Samples ◽  
Scanning Microwave Microscopy

Reference samples are commonly used for the calibration and quantification of nanoscale electrical measurements of capacitances and dielectric constants in scanning microwave microscopy (SMM) and similar techniques. However, the traceability of these calibration samples is not established. In this work, we present a detailed investigation of most possible error sources that affect the uncertainty of capacitance measurements on the reference calibration samples. We establish a comprehensive uncertainty budget leading to a combined uncertainty of 3% in relative value (uncertainty given at one standard deviation) for capacitances ranging from 0.2 fF to 10 fF. This uncertainty level can be achieved even with the use of unshielded probes. We show that the weights of uncertainty sources vary with the values and dimensions of measured capacitances. Our work offers improvements on the classical calibration methods known in SMM and suggests possible new designs of reference standards for capacitance and dielectric traceable measurements. Experimental measurements are supported by numerical calculations of capacitances to reveal further paths for even higher improvements.

Errors of In Situ Illuminance Measurements

2016 ◽  
Vol 824 ◽  
pp. 676-683
Author(s):  
Michaela Hlásková ◽  
Lenka Gábrová ◽  
František Vajkay
Keyword(s):  
Measurement Errors ◽  
Daily Basis ◽  
Lighting Design ◽  
Public Health Authority ◽  
Construction Work ◽  
Measurement Instruments ◽  
Artificial Lighting ◽  
Lighting Conditions ◽  
Overcast Sky

Lighting conditions in buildings are verified by experts on a daily basis. Such verifications may be done at several phases in various ways. In the field of daylighting, it is common to make an assessment within the pre-design and in-design phases of a construction work throughout calculations, only rarely by measurements. This approach is the opposite of artificial lighting design, which is done within the in-design phase by calculations and is verified by measurements in post-realization phase. The verification of artificial lighting design is required by the building and public health authority otherwise buildings cannot be approved to use. In the field of daylighting, measurements could be performed as well, nevertheless those are often problematic because regulations usually require fulfilments of the daylight factor which can be determined only under CIE overcast sky. Howbeit, both artificial lighting and daylighting measurements are influenced by many errors, e.g. errors of light measurement instruments, measurement conditions, measurement methods and human factor. The paper is focused on this aspect of lighting design, more specifically on the daylighting measurement errors.

ISO/TS 20914:2019 – a critical commentary

2020 ◽  
Vol 58 (8) ◽  
pp. 1182-1190 ◽  
Author(s):  
Ian Farrance ◽  
Robert Frenkel ◽  
Tony Badrick
Keyword(s):  
Measurement Uncertainty ◽  
Measurement Data ◽  
International Normalized Ratio ◽  
Medical Laboratory ◽  
Uncertainty In Measurement ◽  
Medical Laboratories ◽  
Functional Relationships ◽  
Critical Commentary ◽  
Combined Uncertainty ◽  
Expression Of Uncertainty

AbstractThe long-anticipated ISO/TS 20914, Medical laboratories – Practical guidance for the estimation of measurement uncertainty, became publicly available in July 2019. This ISO document is intended as a guide for the practical application of estimating uncertainty in measurement (measurement uncertainty) in a medical laboratory. In some respects, the guide does indeed meet many of its stated objectives with numerous very detailed examples. Even though it is claimed that this ISO guide is based on the Evaluation of measurement data – Guide to the expression of uncertainty in measurement (GUM), JCGM 100:2008, it is with some concern that we believe several important statements and statistical procedures are incorrect, with others potentially misleading. The aim of this report is to highlight the major concerns which we have identified. In particular, we believe the following items require further comment: (1) The use of coefficient of variation and its potential for misuse requires clarification, (2) pooled variance and measurement uncertainty across changes in measuring conditions has been oversimplified and is potentially misleading, (3) uncertainty in the results of estimated glomerular filtration rate (eGFR) do not include all known uncertainties, (4) the international normalized ratio (INR) calculation is incorrect, (5) the treatment of bias uncertainty is considered problematic, (6) the rules for evaluating combined uncertainty in functional relationships are incomplete, and (7) specific concerns with some individual statements.

Numerical study on pressure prediction and its main influence factors in pneumatic conveyors

2010 ◽  
Vol 65 (23) ◽  
pp. 6247-6258 ◽  
Author(s):  
A.C. Ma ◽  
K.C. Williams ◽  
J.M. Zhou ◽  
M.G. Jones
Keyword(s):  
Numerical Study ◽  
Influence Factors ◽  
Main Influence

Application of Image Analysis Based on Canny Operator Edge Detection Algorithm in Measuring Railway Out-of-Gauge Goods

2014 ◽  
Vol 912-914 ◽  
pp. 1172-1176 ◽  
Author(s):  
Yong Han ◽  
Mu Qiao ◽  
Xue Wan ◽  
Qing Chang
Keyword(s):  
Edge Detection ◽  
Measurement Errors ◽  
Detection Algorithm ◽  
Digital Measurement ◽  
Contour Extraction ◽  
Mathematical Software ◽  
Canny Operator ◽  
Edge Detection Algorithm ◽  
Measurement Results ◽  
Transport Safety

In order to guarantee out-of-gauge freight transport safety, it is necessary to study digital measurement to improve measuring accuracy for out-of-gauge goods which is very difficult to master outline dimension. The process of edge detection and the algorithm of canny operator edge detection were introduced in this paper. Taking the transformer for example, contour extraction was carried out on the end and the widths of transverse and longitudinal height are measured through the mathematical software MATLAB. Finally, measurement results are validated based on the known data. The results showed that canny operator has high calculate precision, and the closer to the part calibrated with pixel calibration, smaller the measurement errors are.

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