Uncertainty Calculation of Roundness by Automatic Differentiation

2010 ◽  
Vol 437 ◽  
pp. 217-221
Author(s):  
Jia Chun Lin ◽  
Michael Paul Krystek ◽  
Zhao Yao Shi
Keyword(s):  
Measurement Uncertainty ◽  
Automatic Differentiation ◽  
Uncertainty In Measurement ◽  
Uncertainty Calculation ◽  
Measurement Results ◽  
Coordinate Metrology ◽  
Data Points ◽  
Roundness Deviation ◽  
Expression Of Uncertainty ◽  
Roundness Measurement

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 roundness measurement either no uncertainty value is given, or the calculation is not based on the model of the respective association criterion for the geometrical feature, because no suitable measurement uncertainty calculation procedure does exist. For the case of roundness measurement in coordinate metrology, this paper will suggest algorithms for the calculation of the measurement uncertainty of the roundness deviation based on the two mainly used association criteria LSC and MZC. The calculation of the sensitivity coefficients for the uncertainty calculation can be done by automatic differentiation, in order to avoid introducing additional errors by the traditional difference quotient approximations. The proposed methods are exact and need as input data only the measured co-ordinates of the data points and their associated uncertainties.

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.

scholarly journals A General Mathematical Approach Based on the Possibility Theory for Handling Measurement Results and All Uncertainties

Metrology ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 76-92
Author(s):  
Simona Salicone ◽  
Harsha Vardhana Jetti
Keyword(s):  
Measurement Uncertainty ◽  
Possibility Theory ◽  
Mathematical Approach ◽  
Lexical Meaning ◽  
Uncertainty In Measurement ◽  
Complete Knowledge ◽  
Measurement Results ◽  
The One ◽  
Expression Of Uncertainty

The concept of measurement uncertainty was introduced in the 1990s by the “Guide to the expression of uncertainty in measurement”, known as GUM. The word uncertainty has a lexical meaning and reflects the lack of exact knowledge or lack of complete knowledge about the value of the measurand. Thanks to the suggestions in the GUM and following the mathematical probabilistic approaches therein proposed, an uncertainty value can be found and be associated to the measured value. In the last decades, however, other methods have been proposed in the literature, which try to encompass the definitions of the GUM, thus overcoming its limitations. Some of these methods are based on the possibility theory, such as the one known as the RFV method. The aim of this paper is to briefly recall the RFV method, starting from the very beginning and the initial motivations, and summarize in a unique paper the most relevant obtained results.

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.

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.

scholarly journals Making roundness measurement applications and control systems on the Roundness Tester Machine

2019 ◽  
Vol 63 (3) ◽  
pp. 17-21
Author(s):  
Dodi Sofyan Arief ◽  
◽  
Eko Jadmiko ◽  
Adhy Prayitno ◽  
Muftil Badri ◽  
...  
Keyword(s):  
Control Systems ◽  
Measurement Data ◽  
Rotating Speed ◽  
Center Point ◽  
Global Quality ◽  
Measurement Results ◽  
Roundness Deviation ◽  
And Control ◽  
Dial Indicator ◽  
Roundness Measurement

Dial indicator is a comparison device usually used in industrial activities, especially in production. To make measurements at this time must be supported by technology that can facilitate operators when using it and when analyzing measurement results. Involving the programme and microcontroller are a solution to developing in roundness measurement, and then the results can be more accurate or thorough between the readable values read from the measuring instrument with the actual value of varying the amount of data. Roundness application is a program that can input measurement data automatically and can do calculations directly. Then, it can display a reference circle, a table that calculates the values of X, Y, R, X’, Y’, R’, Roundness Deviation, Run out Concentricity or a shift in the center point and also the center point shift or Theta. In measuring roundness, the test object is used the Standard Mandrel which has been certified by PT. Global Quality Indonesia, by determining three points or positions, namely in the first position the amount of data is 180, in the second position the amount of data is 90 and in the third position, the amount of data is 60 with a rotating speed of 15 mm/s. The results of the reference circle can be seen in each calculation in each position, in the second position the roundness deviation values are approaching of the Mandrel.

scholarly journals Two approaches for measurement uncertainty estimation: which role for bias? Complete blood count experience

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hatice Bozkurt Yavuz ◽  
Süleyman Caner Karahan ◽  
Hüseyin Yaman ◽  
Asım Örem ◽  
Yüksel Aliyazıcıoğlu
Keyword(s):  
Measurement Uncertainty ◽  
Blood Count ◽  
Concentration Level ◽  
Complete Blood Count ◽  
Performance Expectations ◽  
Uncertainty Calculation ◽  
Measurement Results ◽  
Measurement Uncertainty Estimation ◽  
Quality Control Data ◽  
Different Levels

Abstract Objectives Measurement uncertainty is described as a magnitude indicates the distribution of the measurement results. AACB Guideline suggests that bias should not be included in the uncertainty calculation contrary to Nordtest Guideline. The aim of the study is to calculate the uncertainty values of certain complete blood count (CBC) parameters and evaluate the contribution of bias. Methods This retrospective study was performed with the quality control data of January–December 2017 of two different CBC autoanalyser models (Beckman Coulter LH780 and DXH800). Measurement uncertainties were calculated according to AACB and Nordtest Guidelines. Imprecision, i.e. measurement uncertainty, varies with concentration. Imprecision values of user manuals, as performance characteristics of autoanalyzers, were used for assessment. Results User manuals imprecision values of different levels of platelets are between 3.3 and 14%. As the concentrations of platelets decrease, imprecision is observed to increase. This is expected to be parallel with measurement uncertainty. Contrary to user manuals, uncertainty values of AACB found to be so close to each other (between 3.41% and 4.80%), regardless of concentration level. However Nordtest guideline is more compatible with user manuals (between 6.97% and 15.35%). Conclusions When evaluated with the performance expectations, bias should be used in measurement uncertainty. Calculation of uncertainty for different concentration level is also important. Amaç Ölçüm belirsizliği, bir büyüklük olarak ölçüm sonuçlarının dağılımını ifade eder. AACB Kılavuzu, Nordtest Kılavuzunun aksine, biasın belirsizlik hesaplamasına dahil edilmesini önermemektedir. Çalışmanın amacı, belirli tam kan sayımı (CBC) parametrelerinin belirsizlik değerlerini hesaplamak ve biasın katkısını değerlendirmektir. Gereç ve Yöntemler Bu retrospektif çalışma, iki farklı CBC otoanalizör modelinin (Beckman Coulter LH780 ve DXH800) Ocak-Aralık 2017 kalite kontrol verileriyle gerçekleştirildi. Ölçüm belirsizlikleri AACB ve Nordtest Kılavuzlarına göre hesaplandı. İmpresizyon, dolayısıyla ölçüm belirsizliği, konsantrasyona göre değişir. Belirsizlik sonuçlarını değerlendirmede otoanalizörlerin kullanım kılavuzlarında yer alan impresizyona dayalı performans özellikleri kullanılmıştır. Bulgular Farklı trombosit düzeylerinin kullanım kılavuzlarındaki impresizyon değerleri %3.3-%14 arasındadır. Trombosit konsantrasyonu düştükçe impresizyon artar. Bunun ölçüm belirsizliği ile paralel olması beklenir. Kullanım kılavuzlarının aksine, AACB’ye göre hesaplanan belirsizlik değerleri, konsantrasyon seviyesinden bağımsız olarak birbirine çok yakın (%3.41–%4.80 arasında) bulundu. Bununla birlikte, Nordtest kılavuzunun sonuçları,otoanalizörlerin kullanım kılavuzları ile daha uyumlu bulundu (%6.97–%15.35 arasında). Sonuç Performans beklentileri ile değerlendirildiğinde, ölçüm belirsizliğinde bias kullanılmalıdır. Farklı konsantrasyon seviyeleri için belirsizliğin ayrı ayrı hesaplanması da önemlidir.

scholarly journals STUDI ANALISIS KETIDAKPASTIAN HASIL KALIBRASI TIMBANGAN DAN MISTAR TERHADAP KEBERTERIMAAN PENGUJIAN GRAMATUR KERTAS (STUDY ON ANALYSIS OF UNCERTAINTY OF CALIBRATED VALUE FOR BALANCE AND RULER FOR THE ACCEPTANCE OF PAPER GRAMMAGE TESTING)

2016 ◽  
Vol 6 (02) ◽  
Author(s):  
Darmawan Darmawan ◽  
Titik Istirohah
Keyword(s):  
Evaluation Method ◽  
Testing Instrument ◽  
Calibration Laboratory ◽  
Iso 17025 ◽  
Uncertainty In Measurement ◽  
Iso Gum ◽  
Uncertainty Calculation ◽  
Value Measurement ◽  
Measurement Uncertainty Evaluation ◽  
Expression Of Uncertainty

Study on analysis of uncertainty of calibrated value for balance and steel ruler for the acceptance of paper grammage testing that refers to SNI ISO 536 : 2010 (grammage testing method) and SNI 14-0440-2006 (paper and carton grammage) has been done. Testing instrument must be calibrated to ensure the testing value/measurement appropriate with expected specification refers to ISO 17025 : 2008. From calibration value gained conventional truth value and uncertainty of testing instrument. Uncertainty calculation refers to “Guide to the Expression of Uncertainty in Measurement”- ISO GUM, is a reference and measurement uncertainty evaluation method that have been received internationally. This reference is also one of reference documents in ISO 17025 : 2008 (competence requirements of examination and calibration laboratory). The evaluation test showed that the deviation value is less than 4%, so that it complies with the allowed tolerance which is also 4%. The result of testing evaluation and calibration showed that balance and ruler were used in Paper Testing Laboratory of Center for Pulp and Paper was appropriate with grammage testing prerequirement. ABSTRAKStudi analisis ketidakpastian hasil kalibrasi timbangan dan mistar baja terhadap keberterimaan uji gramatur kertas yang mengacu pada SNI ISO 536 Cara uji gramatur dan SNI 14-0440-2006 Gramatur kertas dan karton telah dilakukan. Untuk menjamin hasil uji/ pengukuran sesuai dengan spesifikasi yang diinginkan menurut ISO 17025 Syarat-syarat kompetensi Laboratorium Pengujian dan Laboratorium Kalibrasi maka alat uji/ukur harus dikalibrasi. Dari hasil kalibrasi diperoleh nilai kebenaran konvensional alat ukur beserta ketidakpastiannya. Perhitungan ketidakpastian mengacu pada ISO GUM “Guide to the Expression of Uncertainty in Measurement”, yang merupakan panduan dan metode evaluasi ketidakpastian pengukuran yang diterima secara internasional. Acuan ini juga sebagai salah satu dokumen acuan dalam ISO 17025 . Dari hasil evaluasi hasil uji diperoleh penyimpangan kurang dari 4%, sehingga memenuhi toleransi yang diizinkan yaitu 4 %. Kesimpulan dari studi ini menjelaskan bahwa timbangan dan mistar baja yang digunakan oleh Laboratorium Uji Kertas Balai Besar Pulp dan Kertas memenuhi syarat uji gramatur. Kata kunci: kalibrasi, ketidakpastian, gramatur, akurasi, toleransiKata kunci: kalibrasi, ketidakpastian, gramatur, akurasi, toleransi

scholarly journals Uncertainties of ISO 3382-3 sound pressure level quantities

Acta Acustica ◽  
2021 ◽  
Vol 5 ◽  
pp. 27
Author(s):  
Moritz Schneider ◽  
Jan Selzer ◽  
Jörg Rissler ◽  
Andrea Wolff ◽  
Florian Schelle
Keyword(s):  
Measurement Uncertainty ◽  
Sound Pressure ◽  
Technical Note ◽  
Acoustic Properties ◽  
Mathematical Framework ◽  
Limit Values ◽  
Uncertainty In Measurement ◽  
Uncertainty Estimates ◽  
Open Plan ◽  
Expression Of Uncertainty

The ISO 3382-3 standard uses the measurable sound pressure based parameters D2,S and Lp,A,S,4 m to describe the acoustic properties of open-plan offices. As yet however, no treatment of the measurement uncertainty of these parameters according to the Guide to the expression of Uncertainty in Measurement (GUM) is to be found in the peer-reviewed literature. This technical note therefore describes how the measurement uncertainty can be declared according to GUM. The mathematical framework presented here can be used and expanded by other laboratories to derive their own uncertainty estimates. It is also applied in this document to 44 measurements yielding combined uncertainties for D2,S of 0.55 dB ≤ $ {\sigma }_{c,{D}_{2,\mathrm{S}}}$ ≤ 0.67 dB and for Lp,A,S,4 m of 0.19 dB ≤ $ {\sigma }_{c,{L}_{p,\mathrm{A},\mathrm{S},4\enspace \mathrm{m}}}$ ≤ 0.83 dB. The implications of this result are discussed with regard to limit values in technical regulations.

scholarly journals Design study for a multicomponent transducer for wind turbine test benches

2020 ◽  
Vol 9 (2) ◽  
pp. 239-249
Author(s):  
Jonas Gnauert ◽  
Georg Jacobs ◽  
Stefan Kock ◽  
Dennis Bosse ◽  
Benjamin Janik
Keyword(s):  
Measurement Uncertainty ◽  
Wind Turbine ◽  
Degrees Of Freedom ◽  
Design Study ◽  
Operational Conditions ◽  
Uncertainty In Measurement ◽  
Fe Simulations ◽  
Transducer Design ◽  
6 Degrees Of Freedom ◽  
Expression Of Uncertainty

Abstract. This paper covers the design study of a multicomponent transducer (MCT) for wind turbine test benches. The MCT will cover the characteristics of wind turbines in the power range of up to 6 MW. The motivation to develop a MCT such as this is to provide satisfying measurement accuracy of loads and moments for all 6 degrees of freedom in order to reduce the uncertainty in the traceability of the drive train behavior due to the applied loads. Therefore, the estimation of the measurement uncertainty is significant with respect to evaluating the design of the MCT. First, the design process of the MCT is briefly introduced. Second, the strain-gauge-based transducer design is investigated under operational conditions (e.g., torque and multiaxial loads) using finite element (FE) simulations to determine the crosstalk effects. Finally, the measurement uncertainties of all quantities are estimated based on these FE simulations according to the type B evaluation of the “Guide to the Expression of Uncertainty in Measurement” (GUM; JCGM, 2010), including metrological aspects (e.g., linearity deviation and hysteresis) and the crosstalk. It can be shown that the MCT has great potential to significantly improve the measurement uncertainty for the applied wind loads on a wind turbine test bench.

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