A New Calibration Facility for the UK’s National Gear Metrology Laboratory

2003 ◽  
Author(s):  
R. C. Frazer ◽  
P. Mancasola ◽  
G. Mikoleizig
Keyword(s):  
Measurement Uncertainty ◽  
Uncertainty Assessment ◽  
Measuring Instruments ◽  
Calibration Facility ◽  
The Uk

The paper discusses the calibration and measurement uncertainty requirements of the UK gear industry. It makes particular reference to the new ISO documents: Draft ISO 18653 and draft TR 10064-5 that are being developed by ISO TC60/WG2 that describe the calibration of gear measuring instruments and measurement uncertainty assessment. Further, the paper the describes initial tests on the performance of a new Klingelnberg P65 Gear Measuring Centre selected by the UK’s National Gear Metrology Laboratory as the platform for improving gear calibration in the UK.

Research of Wet Gas Experimental Facility with Adjustable and Intermediate Pressure

2012 ◽  
Vol 220-223 ◽  
pp. 875-879
Author(s):  
Ying Xu ◽  
Cun Yin ◽  
Zheng Hai Long
Keyword(s):  
Measurement Uncertainty ◽  
Flow Rate ◽  
Gas Flow ◽  
Uncertainty Assessment ◽  
Experimental Facility ◽  
Rate Range ◽  
Intermediate Pressure ◽  
Loop Design ◽  
Wet Gas ◽  
Flow Rate Range

In order to better simulate the flowing condition of wet gas, Tianjin University has designed and built up a wet gas flow experimental facility with adjustable and intermediate pressure in the flow laboratory. The designed pressure of the facility which used standard meter method and dual closed-loop design is 4MPa. The experiment medium is air and water, and the highest operation pressure is 1.6MPa. The gas flow rate range is 3~1000m3/h, and the liquid flow rate range is 0.05~8 m3/h. This article includes the structure introduction of the facility and the calculation of pressure loss of the system, etc. By the uncertainty assessment for the discussed facility, the conclusion is stated that the facility’s gas measurement uncertainty is 1% and the facility’s liquid measurement uncertainty is 0.35%.

scholarly journals Measuring uncertainty assessment of an experimental device used to determine the thermo-optico-physical properties of translucent construction materials

2021 ◽  
Author(s):  
Mélanie Delort ◽  
Damien Ali Hamada FAKRA ◽  
Bruno Mallet-Damour ◽  
Jean Claude Gatina
Keyword(s):  
Measurement Uncertainty ◽  
Construction Materials ◽  
Optical Transmittance ◽  
Uncertainty Assessment ◽  
Physical Models ◽  
Experimental Device ◽  
Optical Absorbance ◽  
New Device ◽  
Uncertainty Estimates ◽  
Experimental Apparatus

Abstract Studying thermo-optical (i.e., thermal conductivity, optical re ectance, optical transmittance, and optical absorbance) properties of construction materials is essential for improving human comfort within a building. Typically, these properties are measured independently using specific equipment. The emerging of new innovative construction structures, such as translucent materials, makes the experimental characterization of these properties more challenging to observe. Recently, a new device, called MultiCoefMeter (McM), which rapidly and simultaneously measures all these properties, has been created. The study described in this article covers the calculation technique for estimating measurement uncertainties linked to morphology, the component parts, and the physical formula of the experimental apparatus. The measurement uncertainty estimates are obtained from knowledge of the color of the system's walls, placement, and form of the McM components, placement of measurement sensors, and the application of measurement collection equipment. Therefore, a thorough calculation analysis was performed on the sub-systems. Calculations are divided between two categories: those based on mathematical tools and information given by the makers, and those based on experimental observations obtained during reliability testing. These uncertainties originate from statistical tools, geometric tolerance of the system, comparison with standards, and the error propagation laws of the physical models link with the device. All these uncertainties were summed up and given a global value, no more than 5%, conforming to the ASTM standard (E1225). Finally, a general method to quantify measurement uncertainty value of any experimental device was proposed.

scholarly journals Evaluation and Optimization of Task-oriented Measurement Uncertainty for Coordinate Measuring Machines Based on Geometrical Product Specifications

2018 ◽  
Vol 9 (1) ◽  
pp. 6 ◽  
Author(s):  
Yinbao Cheng ◽  
Zhongyu Wang ◽  
Xiaohuai Chen ◽  
Yaru Li ◽  
Hongyang Li ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Evaluation Model ◽  
Optimization Method ◽  
Practical Significance ◽  
Measuring Instruments ◽  
Coordinate Measuring Machines ◽  
Measurement Instruments ◽  
Practical Applications ◽  
Geometric Product ◽  
Task Oriented

Measuring instruments are intended to be intelligent, precise, multi-functional and developing multidirectionally, scientific, and reasonable; the reliable evaluation of measurement uncertainty of precision instruments is also becoming more and more difficult, and the evaluation of the Coordinate Measuring Machines (CMM) measurement uncertainty is among the typical problems. Based on Geometric Product Specification (GPS), this paper has systematically studied the CMM uncertainty for evaluating the size and geometrical errors oriented toward measurement tasks, and thus has realized the rapid and reliable evaluation of the CMM uncertainty for task-oriented measurement. For overestimation of the CMM uncertainty for task-oriented measurements in the initial evaluation, a systematic optimization solution has been proposed. Finally, the feasibility and validity of the evaluation model and the optimization method have been verified by three different types of measurement examples of diameter, flatness and perpendicularity. It is typical and representative to systematically solve the problem of the CMM uncertainty for evaluating the measurement tasks targeted at dimensions and geometric errors, and the research contents can be effectively applied to solve the uncertainty evaluation problems of other precision instruments, which are of great practical significance not only for promoting the combination of modern uncertainty theory and practical applications but also for improving the application values of precision measurement instruments.

Total haemoglobin – a reference measuring system for improvement of standardisation

2020 ◽  
Vol 58 (8) ◽  
pp. 1314-1321
Author(s):  
Denis Grote-Koska ◽  
Rainer Klauke ◽  
Patricia Kaiser ◽  
Udo Kramer ◽  
Rainer Macdonald ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Measurement Range ◽  
Measuring System ◽  
Measuring Instruments ◽  
National Metrology Institute ◽  
Reference Measuring ◽  
Target Values ◽  
Method Optimization ◽  
Total Haemoglobin ◽  
Hb Concentration

AbstractBackgroundTotal haemoglobin (Hb) concentration in blood belongs to the most requested measurands, and the HiCN method (hemiglobincyanide) is accepted as a reference. Although the reaction principle is clearly characterised, measurement conditions and settings are not consistently defined, some of them influencing the results. An improvement of standardisation is the object.MethodsAfter method optimization, measurement results between different calibration laboratories (CL) were compared with each other and also with results of the National Metrology Institute of Germany (PTB), with target values of certified reference material, within the RELA scheme, and to >1500 results from routine laboratories.ResultsOverall deviations between three CLs were ≤0.5% (n = 24 samples) in a measurement range of 20 g/L to 300 g/L. A CV of 0.4% was determined in pooled blood (1 year long-term imprecision, 99.0%–101.1% recovery of the mean). For selected measurements (n = 4 samples) the PTB participated without significant differences to three CLs, and no significant differences were observed comparing CLs to certified values of reference materials. The expanded measurement uncertainty (probability 95%) was estimated as 1.1%.ConclusionsA reference measuring system, comprising measuring instruments and other devices, including reagents and supply, to generate reference measurement values for total Hb concentration of high accuracy and low measurement uncertainty is presented. Measurement parameters are investigated and defined. The reference measuring system is ready to offer service to EQA providers and to the IVD industry for certifying control materials or calibrators.

METHODOLOGY FOR EVALUATION THE UNCERTAINTY OF MEASUREMENT OF MECHANICAL STRESS BY THE ULTRASONIC METHOD WITH THE HELP OF AN OPTICAL-ACOUSTIC SEPARATE-COMBINED TRANSDUCER

2021 ◽  
pp. 56-61
Author(s):  
A. V. Fedorov ◽  
V. A. Bychenok ◽  
I. V. Berkutov ◽  
I. E. Alifanova
Keyword(s):  
Measurement Uncertainty ◽  
Ultrasonic Wave ◽  
Test Object ◽  
Ultrasonic Method ◽  
Mechanical Stresses ◽  
Ultrasonic Waves ◽  
Measuring Instruments ◽  
Acoustic Transducer ◽  
Head Waves ◽  
Uncertainty Of Measurements

The work is devoted to the ultrasonic method for controlling mechanical stresses using ultrasonic head waves. The speed of the head ultrasonic wave is the highest, which allows it to be recorded stably among other types of ultrasonic waves and noises. To determine mechanical stresses, registration of the relative change in the velocity of propagation of the head ultrasonic wave is used, corrected for the change in the measured value caused by the change in the temperature of the test object. Thus, mechanical stresses are not measured directly, but the sources of uncertainty are the results of measurements of the propagation velocity of the head ultrasonic wave, the temperature of the environment and the test object, the coefficients of acoustoelastic and thermoacoustic coupling, and the parameters of the optical-acoustic transducer. The contribution of each of these factors to the results of measurements of mechanical stresses is estimated. On the basis of GOST 34100.3–2017, a method has been developed for asessing the uncertainty of measurements of mechanical stresses by the ultrasonic method using head waves. The dependence of the expanded measurement uncertainty on the value of the measured mechanical stresses was obtained. This dependence shows that measurements of mechanical stresses in the range of less than 100 MPa have an uncertainty of more than 10 % of the measured value. When measuring mechanical stresses over 200 MPa, the measurement uncertainty will not exceed 4 % (at a confidence level of 95 %).The proposed approach to assessing the uncertainty of measurements of mechanical stresses can be useful in the development of requirements for the used measuring instruments, alignment samples and control objects, as well as in the development of methods for monitoring mechanical stresses by the ultrasonic method using an optical-acoustic separate-combined transducer.

Formulation of Influence of Machine Geometric Errors on Five-Axis On-Machine Scanning Measurement by Using a Laser Displacement Sensor

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Soichi Ibaraki ◽  
Yoshihiro Kimura ◽  
Yu Nagai ◽  
Shizuo Nishikawa
Keyword(s):  
Measurement Uncertainty ◽  
Spherical Surface ◽  
Uncertainty Assessment ◽  
Displacement Sensor ◽  
Experimental Comparison ◽  
Geometric Errors ◽  
Laser Displacement Sensor ◽  
Low Pass ◽  
Continuous Scanning ◽  
Five Axis

For on-machine measurement of workpiece position, orientation, and geometry on machine tools, five-axis continuous (scanning) measurement by using a laser displacement sensor has a strong advantage in its efficiency, compared to conventional discrete measurement using a touch-triggered contact probe. In any on-machine measurement schemes, major contributors to their measurement uncertainty are error motions of the machine tool itself. This paper formulates the influence of geometric errors of rotary axis average lines on the measurement uncertainty of the five-axis on-machine measurement by using a laser displacement sensor. To validate the present simulator, experimental comparison of measured and simulated trajectories is conducted on five-axis on-machine measurement of a precision sphere of the precalibrated geometry. For total 28 paths measured on the spherical surface, an error in the simulated trajectories from measured trajectories (properly low-pass filtered) was at maximum 5 μm. Uncertainty assessment demonstration for more practical application example of a turbine blade measurement is also presented.

scholarly journals Validation and Measurement Uncertainty Assessment of a Microbiological Method Using Generalized Pivotal Quantity Procedure and Monte-Carlo Simulation

2018 ◽  
Vol 101 (4) ◽  
pp. 1205-1211
Author(s):  
Saad Alaoui Sossé ◽  
Taoufiq Saffaj ◽  
Bouchaib Ihssane
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Measurement Uncertainty ◽  
Uncertainty Assessment ◽  
Tolerance Interval ◽  
Alternative Procedure ◽  
Pivotal Quantity ◽  
Statistical Tool ◽  
Generalized Pivotal Quantity ◽  
Escherichia Coli Bacteria

Abstract Recently, a novel and effective statistical tool called the uncertainty profile has been developed with the purpose of graphically assessing the validity and estimating the measurement uncertainty of analytical procedures. One way to construct the uncertainty profile is to compute the β-content, γ-confidence tolerance interval. In this study, we propose a tolerance interval based on the combination of the generalized pivotal quantity procedure and Monte-Carlo simulation. The uncertainty profile has been applied successfully in several fields. However, in order to further confirm its universality, this newer approach has been applied to assess the performance of an alternative procedure versus a reference procedure for counting of Escherichia coli bacteria in drinking water. Hence, the aims of this research were to expose how the uncertainty profile can be powerfully applied pursuant to ISO 16140 standards in the frame of interlaboratory study and how to easily make a decision concerning the validity of the procedure. The analysis of the results shows that after the introduction of a correction factor, the alternative procedure is deemed valid over the studied range because the uncertainty limits lie within the acceptability limits set at ±−0.3 log unit/100 ml for a β = 66.7% and γ = 90%.

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