bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue Crack Propagation Path and Life Prediction Based on XFEM
Authors: He Longlong , Liu Zhifang , Gu Junjie , Wang Jinliang , Men Kunfa
Published: September 2019

Based on the theory of linear elastic fracture mechanics, the relationships between material constants c3, c4 required in Abaqus and constants C, m in Paris formula are derived. Then extended finite element method (XFEM) of Abaqus software is used to is used to predict the crack propagation path and life of the plate with center inclined through crack and typical stiffened wing spar with initial crack under the constant amplitude fatigue load. The results show that the predicted crack propagation path is in good agreement with the experimental results, and the crack propagation life error is less than 6.3%. It also shows that this method can accurately predict the fatigue crack growth path and life of two-dimensional and three-dimensional complex structures under constant amplitude loads. This study can provide an effective way for damage tolerance analysis of structures and has certain engineering application value.
Research on Influence of CMM Sampling Points on Detection of Feature Parameters for Turbine Blade
Authors: Bu Kun , Zhang Xiandong , Ren Shuaijun , Qiu Fei , Tian Guoliang
Published: September 2019

Sampling plan is an essential part for measuring profile of turbine blade with coordinates measuring machine(CMM), and the detection of feature parameters is a key component of turbine blade inspection. However, the influence of the sampling strategy on the blade feature parameters evaluation has been rarely studied. In order to understand the correlation between the sampling strategy and the accuracy of blade profile feature parameters, firstly, the extraction methods of turbine blade feature parameters were proposed, and these methods were compiled into an executable program TBGeoInspect. Secondly, based on the level principle, the unified mathematical representations of uniform sampling, curvature-based sampling, chord deviation sampling, weighted curvature-based sampling, and curvature-arc length sampling were given. The effect of these five sampling algorithms on the accuracy of turbine blade profile feature parameters was gained through simulation and experiment results of blade sampling. The results validate that the uncertainty of turbine blade feature parameters and sectional curve fitting error are lowest with curvature-arc length sampling method under the same number of sampling points.
A Recognition Algorithm for Modulation Schemes by Convolution Neural Network and Spectrum Texture
Authors: Bai Pengyuan , Xu Hua , Sun Li
Published: September 2019

The recognition of modulation schemes for communication signals is an important part of communication surveillance and spectrum monitoring. An algorithm based on deep learning and spectrum texture is proposed to recognize modulation schemes. Based on imperceptible differences among various spectrums of modulation schemes, the algorithm uses Convolution Neural Network to capture the features of image texture and thus classify the features with a SOFTMAX classifier. The experiment shows the algorithm performs better than traditional algorithm based on feature parameters, while the features captured can better reveal the signal detail and reduces effort on feature parameter design.
The European Metrology Cloud: Impact of European Regulations on Data Protection and the Free Flow of Non-Personal Data
Authors: Thiel Florian , Wetzlich Jan
Published: September 2019

New digital technologies, such as cloud computing, big data, artificial intelligence and the Internet of Things (IoT) are designed to maximize efficiency, enable economies of scale and develop new services. They offer benefits to users, such as agility, productivity, speed of deployment and autonomy. In the sector of Legal Metrology, it must be ensured that digital system architectures, digital services, and digital infrastructures are legally compatible. To benefit the stakeholders in this sector, the industry, the notified bodies and the market surveillance/verification authorities alike, the digital transformation of Legal Metrology shall remove barriers to innovation within the legal processes and reduce costs and time to market for new digital products. To this end a European consortium has formed to establish a digital quality infrastructure; the “European Metrology Cloud”, designed to support the processes of conformity assessment and market surveillance/verification and the development of reference architectures and new technology- and data-driven services for this infrastructure. With this approach, the digital single market that the European Commission envisions will be fostered. This article analyzes how recent regulations within the digital single market strategy of the commission - the Data Protection Police Directive (2016/679/EU) and the Regulation on a framework for the free flow of non-personal data in the European Union (Regulation (EU) 2018/1807) – may be integrated into the European Metrology Cloud initiative to, e.g. guaranty that its underlying Blockchain approach complies to these norms and exploit their benefits.
Calibration 4.0 – Information system for usage of digital calibration certificates
Authors: Marques Miguel , Sousa João A. , Ribeiro Luís
Published: September 2019

The main goal of this study is to operationalize the emission, exchange and use of digital calibration certificates, through structured information and the specification of a system of information. The purpose of digital calibration certificates, is not only the transformation of a physical format to a digital one, but mainly the application of the real digitalization concept, i.e., the use of digital technologies to change a business model and supply new opportunities with added value. Besides the easiness in the exchange of calibration results, the future development of a system to exchange digital calibration certificates will allow customers to receive and analyze certificates faster, reducing execution times and costs associated to the metrological confirmation process, as well as to avoid human error and their consequences. The application of a system adapted to calibration certificates, and the implementation and testing at a National Measurement Institute as IPQ, based on XML, with examples from different areas will be presented. This study will then result in the creation of national working group in Portugal for the digitalization of calibration certificates to a broader market, with the first trial cases implemented in these two laboratories, INEGI-LAC and IPQ-LNM.
Practical Precision Electrical Impedance Measurement for the 21st Century – EMPIR Project 17RPT04 VersICal
Authors: Power Oliver , Ziolek Adam , Elmholdt Christensen Andreas , Pokatilov Andrei , Nestor Anca , Gumez Gulay , Kučera Jan , Kaczmarek Janusz , Jursza Jolanta , Callegaro Luca , Ribero Luis Filipe , Koszarny Maciej , Marzano Martina , Ortolano Massimo , Kozioł Mirosław , Tran Ngoc Thanh Mai , Rybski Ryszard , D’Elia Vincenzo , Rzodkiewicz Witold
Published: September 2019

The core objective of EMPIR project 17RPT04 VersICaL is to improve the European measurement infrastructure for electrical impedance, with particular emphasis on the capabilities of developing NMIs and calibration centres. The project will seek to exploit the results of existing research on digital impedance bridges (DIBs) by designing, constructing and validating simple, affordable versions suitable to realise the impedance scale in the range 1 nF to 10 μF and 1 mH to 10 H with relative uncertainties in the range 10-5 to 10-6. The first results of the research project, including the bridge designs and details of a polyphase digitally synthesized multichannel source capable of providing voltage outputs of precise ratio and phase are presented.
EMPIR European project for validation of vector array SAR measurement systems
Authors: Allal Djamel
Published: September 2019

In the context of the new international standard IEC 62209-3 developed within IEC Technical Committee TC 106, EURAMET is running European research project Vector SAR with the aim to provide the validation methods, software tools and datasets required for traceable calibration and uncertainty analysis of vector probe array systems that automatically determine the 3D electromagnetic field and Specific Absorption Rate (SAR) mapping using amplitude and phase information through a 3D reconstruction algorithm.
Calibration and measurement capability (CMC) and customer technical qualification
Authors: Fischer Beckert Suelí , Ednan Flôres Renan
Published: September 2019

In the context of metrological confirmation, calibration is an essential process in all quality assurance efforts. Several organizations choose to outsource this activity to accredited laboratories in accordance with the requirements set forth in ISO/IEC 17025: 2017. Companies understand that accredited laboratory has formal recognition of its technical competence to perform the services within its scope of accreditation. The document ILAC P14: 2013 sets out guidelines for the presentation of Calibration and Measurement Capability (CMC). However, when analysing the scope of accredited laboratories in some national calibration bodies, it is possible to observe that, for the same instrument and the same measuring range, different values are attributed to CMC. If the CMC should result from normal calibration operations on the best existing device, what causes this dispersion? How can the customer make effective use of the information contained in accreditation scopes? In order to further standardize the presentation of CMC in accreditation scopes, calibration methods adopted by laboratories should be required to meet the maximum permissible errors established by manufacturers or normative documents. Companies can outsource calibration activities. But the selection of service provider and the interpretation of the results remains a customer assignment. The paper presents an analysis of accreditation scopes of different national calibration bodies and discusses the qualification of those in charge of metrology management, regarding the knowledge and skills required for activity.
A Case Study on the Establishment of a National Quality Infrastructure in Korea
Authors: Yoo Heekyeom
Published: September 2019

Standards are involved in the series of actions of individuals and groups such as governments and markets with different interests and purposes. Standards are created through social and scientific coordination and are used at the national and international level. This study examines the standard governance of Korea, which is structured and implemented around three important elements of national quality infrastructure: standardization, conformity assessment, and metrology, from the legal and organizational perspectives. Article 127 (2) of the Constitution of the Republic of Korea states “the State shall establish a system of national standards” and theFramework Act on National Standardsand theEnforcement Decreeenacted in 1999 for the establishment and implementation of national quality infrastructure. As three pillars of national quality infrastructure, standardization, conformity assessment, and metrology are interrelated and indispensable for each other to provide a consistent and reliable social as well as scientific and technical grounds for development and implementation of national standards. Drawing on the Korean case of national standards in respect to earthquake risk management, this study examines the problems of imbalance and disconnection of these quality management elements. In conclusion, future plans for national quality assurance are suggested from the perspective of a network governance.
The European metrology network for climate and ocean observation
Authors: Woolliams Emma , Pascale Céline , Fisicaro Paola , Fox Nigel
Published: September 2019

EURAMET, the association responsible for coordinating the integrated metrology community in Europe, has recently established European Metrology Networks (EMNs) to support its aim to bring high-quality scientific research and coordinated metrological services to meet the rapidly advancing needs of different stakeholders for metrology. The EMN for Climate and Ocean Observation is one of the initial six EMNs and has been set up as a European coordination body to support the global effort to bring rigorous metrological discipline into the observations that underpin our understanding of the climate and the oceans. This paper describes the network, its activity so far, and its plans.
Use of FTIR spectroscopy for the measurement of CO2 carbon stable isotope ratios
Authors: Rolle Francesca , Sega Michela
Published: September 2019

Carbon dioxide (CO2) is one of the most important long-lived anthropogenic greenhouse gases. Ocean, land and biosphere contribute to take up CO2 emissions, but approximately half of fossil fuel CO2 accumulates in the atmosphere. The study of isotopic composition of CO2 can give useful information for assessing and quantifying the uptake of CO2 in the environmental compartments, as well as for distinguishing natural from anthropogenic carbon in the atmosphere. In this work, an activity for the development of a Fourier Transform Infrared spectroscopy (FTIR) based method for δ13C-CO2 determination in CO2 in air mixtures is presented. The FTIR can be calibrated by a classical approach based on primary calibration gas standards, but an alternative calibration can be based on the generation of synthetic spectra, by means of radiative transfer calculation codes such as the Multiple Atmospheric Layer Transmission (MALT University of Wollongong, Australia). Another software (B-FOS) developed at the Bureau International des Poids et Mesures (BIPM) allows to interface MALT and the FTIR management software. This calibration approach is fast and reliable and can be used when the classical calibration based on reference gas mixtures might be demanding. The uncertainty obtained for δ13C-CO2 measurements is around 0.1 ‰, at a nominal CO2 mole fraction of 400 μmol mol-1 in air.
Metrological references for health care based on entropy
Authors: R Pendrill Leslie , Melin Jeanette , J Cano Stefan ,   the EMPIR NeuroMET 15HLT04 consortium
Published: September 2019

Consistent diagnosis in healthcare relies, in part, on quality assurance of categorical observations, such as responses to ability tests and patient surveys. Linking classifications on such nominal and ordinal scales to decision-making involves a combination of logit transformations and novel entropy-based estimates of measurement information throughout the measurement process. This paper presents how entropy can explain and predict entity attributes (such as task difficulty), instrument ability and resolution, and measurement system response. Cognitive ability studies in the EMPIR NeuroMET project are taken as an example, showing how better understanding of both entity and measurement system attributes leads to more fit-for-purpose and better targeted treatment.
Fictive power source for calibrations in railway systems
Authors: Istrate Daniela , Fortune Dominique
Published: September 2019

The work presented in this paper aims at developing a reference system for laboratory calibration of the Energy Measurement Functions working under AC supply system and actual operating conditions. More precisely, the paper focuses on the design of a fictive power source designed to generate voltage and current waveforms of 15 kV-16.7 Hz and 25 kV-50 Hz, 500 A with harmonics up to 5 kHz.
Position accuracy and repeatability calibration of turn tables by using laser interferometers
Authors: Yüksel İ. Ahmet , Kılınç T. Oytun , Sönmez K. Berk , Ön Aktan Sinem
Published: September 2019

This paper presents how to perform position accuracy calibration of multi axis turntable with a laser interferometer according to ISO-230-2 Determination of accuracy and repeatability of positioning of numerically controlled axes standard [1]. High accurate multi-axis turn tables are frequently used at defense and aviation & space industries. These turn tables are used to control of devices which collect data regarding position. So turn tables shall be calibrated periodically to remain between specification performances criteria. Calibration of a rotary axis of turn tables’ position is commonly performed by using autocollimator and multi-sided polygon systems. Alignment of polygon and autocollimator with turn table axes may have difficulties regarding time requirements and setup of hardware. Laser interferometers can be used as an alternative method to regular calibration of position and repeatability of an axis with advantages considering time requirement and ease of application. In this study, position accuracy and repeatability calibration of a horizontal axis which has ± 3 arc second will be performed and results will be evaluated.
Proficiency testing for the calibration of masses
Authors: HEGRON Lise , GEYNET Boris
Published: September 2019

The CT2M organized in 2018 a european inter-laboratory comparison (ILC) for the calibration of masses. The proficiency testing was particulary intended for the calibration laboratories (accredited or not) but also the testing laboratories carrying out their own calibrations and / or controls of their masses. This circuit took place between April 2018 to October 2018 in five European countries: England, France, Germany, Portugal and Switzerland. The results were processed according to the statistical principle of ISO 13528 [1] and in compliance with the requirements of ISO 17043 [2]. This article presents the organization of this inter-laboratory comparison and the results. The performances of the participants are evaluated and an interpretation of the results is proposed in order to highlight the predominant influence parameters on the mass calibration results (nominal values: 200mg, 2g, 20g, 200g and 20kg).
Challenges of achieving accreditation to ISO 6789-2:2017 – for the calibration of hand torque tools
Authors: Gypps Matthew
Published: September 2019

In recent years hand torque tools have been manufactured and calibrated in accordance with the standard BS EN ISO 6789:2003. A number of flaws were identified with this standard and therefore a revised version BS EN ISO 6789:2017 was released.

The new standard required a significant increase in the number of measurements to be made which in turn created a risk to engineers, from repetitive strain injuries and a potential increase in cost to customers.

As the market leader for calibration with a high demand for accredited calibration, Trescal set the following objectives: minimise risk to Engineers, maintain a cost effective service and be the first non-manufacturer to obtain accreditation to the revised standard.

Significant investment in automated equipment not only reduced the risk of injury to engineers but also reduced calibration times and therefore cost. However the use of automated solutions for calibration of mechanical devices, created a number of challenges when trying to achieve accreditation.

Differences in the interpretation of the ISO standard by national assessment bodies resulted in variations of requirements and timescales for achieving accreditation throughout Europe.

Our presentation will highlight some of these issues.
Inter-laboratory comparison on the calibration of measurements photometric and radiometric sensors
Authors: Sönmez K. Berk , Kılınç T. Oytun , Yüksel İ. Ahmet , Ön Aktan Sinem
Published: September 2019

The competences of the test and calibration laboratories are provided by two complementary methods. The first of these methods is the on-site audit carried out by the administrative and technical committee established by TURKAK (Turkish Accreditation Institution) according to the requirements of TS EN ISO / IEC 17025 [1]. The other technique is interlaboratory comparison and proficiency testing to evaluate laboratory performance and ensure the quality of results. Investing in the right equipment, training personnel, defining methods, documenting, calculating uncertainty, even performing internal verifications do not guarantee reliability or accuracy. It cannot answer the question of whether we can produce the same results as the same testers in the world. It is necessary to prove that the laboratory can actually produce accurate results externally by going through comparison tests with other national/international laboratories.
A versatile electrical impedance calibration laboratory based on a digital impedance bridge
Authors: Elmholdt Christensen Andreas
Published: September 2019

A four-terminal pair fully digital impedance ratio bridge is described. Its principle of operation including balancing procedure and calculation of unknown impedance value is presented. An initial 1:1 ratio check of the bridge has been performed. Systematic errors of the bridge design and actions to deal with these errors are shown.
Robustness studies of oscillation-type density meters with viscoelastic fluids
Authors: Furtado Andreia , Pereira Jorge , Quendera Raquel , Cidade Maria Teresa
Published: September 2019

The oscillation frequencies produced by oscillation-type density meters during the density measurements suffer damping due to the viscosity of Newtonian liquids. The effect of viscoelastic behaviour of non-Newtonian liquids in the damping of these oscillations is still not known. So, 7 viscoelastic liquids were rheologically characterized, resorting to a rheometer, and their density measured in order to provide a deeper insight into the damping effects produced by these types of fluids. To do so, oscillatory data was related with the obtained density deviations. The results of this study will give further insights for the knowledge of the measuring behaviour of these density meters when measuring viscoelastic fluids, one of the scopes of the EMPIR Project 17RPT02-rhoLiq.
Microstructural and spectrophotometric analysis system for metal welding processes
Authors: Filippo Roberto , Capra Pier Paolo , Lai Manuel , Faga Maria Giulia
Published: September 2019

We describe an analysis system for some of the most important methods of metal welding, based on the acquisition, study and comparison of the atomic emission spectra (in the range from 250 nm to 830 nm), hyperspectral imaging between 600 nm and 950 nm wavelengths and microstructural analysis. The radiometric measurement system acquires information while the welding process is in progress and acquired data are then compared with those resulting from the subsequent microstructural analysis. It is known that the process parameters like, for example, the source power or its speed over the parts during welding, significantly affect the mechanical properties and quality of the resulting junction like hardness, porosity, presence of cracks or other damages and so on. On the other hand, these properties and, above all, the changes in the joint features due to unwanted variations in the process parameters or in the materials being welded, can be inferred by studying the microstructure. In this sense, a proper correlation between the in situ spectral analysis and the microstructural properties is of paramount importance for controlling and adjusting the parameters during the process. In line with the requirements of Industry 4.0, the system described is a study of the application of metrology in a production line, designed to increase information about the production parameters of mechanical industry without increasing costs and limiting the complexity of additional installations. In this paper we report a series of experiments performed using LASER and TIG welding systems applied to different metals. The comparison between the welding conditions acquired by the optical systems and the methods of structural analysis are the basis of a project to improve production systems and their automation.
A µKibble balance for direct realisation of small-scale masses and forces
Authors: Jarvis Charlie , Webster Emily , Davidson Stuart , Robinson Ian
Published: September 2019

Kibble balance experiments have allowed the kilogram to be redefined in terms of the Planck constant. Now that the redefinition is in place, the Kibble balance will allow SI traceable mass (or force) to be realised at any value and at any location. A feasibility study for a novel, scalable electrostatic ‘µKibble balance’, based on the National Physical Laboratory (NPL) next-generation Kibble balance system is presented and its expected performance calculated. A µKibble will allowin-situ, dynamic, small-scale (< g) mass measurements without the current precision limitation caused by subdivision of the kilogram. The measurements will be traceable through electrical calibration rather than transferable mass standards. The instrument will have a wide range of applications in both industry and research.
Certified reference materials for breath alcohol control - the ALCOREF project
Authors: Lalere Béatrice , Gantois Fanny , Philipp Rosemarie , Vaslin-Reimann Sophie
Published: September 2019

The Joint Research Project Alcoref “Certified forensic alcohol reference materials” is a multi-partner trans-national project within the targeted call “Research Potential” of the European Metrology Programme for Innovation and Research (EMPIR) launched in 2016. The European Commission has estimated that about one quarter of road traffic deaths are due to alcohol. The European status report on road safety of the World Health Organization Regional Office for Europe therefore stated that, among other measures, better legislation and enforcement of alcohol control is needed in several countries. In particular, the report demands that unrestricted access to alcohol breath testing, using breath analysers of equivalent and agreed standard, should be implemented throughout Europe. These high standards for tests, verification and calibration of breath alcohol analysers should meet some requirements of the recommendation R 126 defined by the International Organization of Legal Metrology (OIML) and European standards (EN 16280 and EN 15964). The specific objective of this project is to establish regional research and metrological capacity for the development of certified forensic alcohol reference materials for the law enforcement of drink-driving regulations.
Primary reference in terms of air kerma for ionizing radiation fields produced by an electrostatic electron accelerator
Authors: Bordy Jean-Marc , Blideanu Valentin , Chapon Arnaud , Dupont Gabriel , Dusciac Dorin , Gouriou Jean , Laine Frederic , Le Roy Maiwenn
Published: September 2019

Based on a radiation field produced by an electrostatic accelerator, a radiation survey meter test and calibration facility has been designed and characterized in terms of air kerma and ambient dose equivalent. The electron beam impinges a tantalum target to produce X-rays. The spectrum has been measured and calculated. Traceability to the International System of units is achieved by means of a calibration with a primary dosimeter for air kerma.
New EMPIR project – Metrology for Drug Delivery
Authors: Batista E. , Furtado A. , Pereira J. , Ferreira M. , Bissig H. , Graham E. , Niemann A. , Timmerman A. , Ogheard F. , Alves e Sousa J.
Published: September 2019

This document presents the scientific and technical objectives, state of the art and expected progress beyond it, and most importantly the expected impact on metrology, science, standards, and society of the new joint research project MeDD II, Metrology for drug delivery (follow up of project MeDD I). It was selected for funding through the EURAMET EMPIR program of the European Commission and the participating countries. The project starts in June 2019 and will last for three years. It involves 15 partners from National and Designated Metrology Institutes, companies, and academia. The main objective is to enable traceable measurements of volume, flow and pressure of existing drug delivery devices (for example infusion pumps and analysers) and inline sensors that work at flow rates lower than 100 nL/min, in order to prevent inaccurate measurement results. This project will also investigate fast changing flow rates, liquid mixing behaviour and occlusion phenomena in multi-infusion systems with the purpose of improving dosing accuracy in each infusion line.
Bayesian approach to uncertainty evaluation: is it always working?
Authors: Ferrero Alessandro , Salicone Simona , Jetti Harsha Vardhana
Published: September 2019

Since the GUM has been published, measurement uncertainty has been defined in terms of the standard deviation of the probability distribution of the values that can be reasonably attributed to the measurand, and it has been evaluated using statistical or probabilistic methods. A debate has always been alive, among the metrologists, on whether a frequentist approach or a Bayesian approach should be followed to evaluate uncertainty. The Bayesian approach, based on some available a-priori knowledge about the measurand seems to prevail, nowadays. This paper starts from the consideration that the Bayesian approach is based on the well-known Bayes theorem that, as all mathematical theorems, is valid only to the extent the assumptions made to prove it are valid. The main question, when following the Bayesian approach, is hence whether these assumptions are satisfied in the practical cases, especially when the a-priori information is combined with the information coming from the measurement data to refine uncertainty evaluation. This paper will take into account some case studies to analyze when the Bayesian approach can be usefully and reliably employed by discussing the amount and pertinence of the available a-priori knowledge.
Development of a dynamic gravimetric calibration method for liquid water flow metering
Authors: Ogheard Florestan
Published: September 2019

According to its mission of national reference laboratory, LNE-CETIAT maintains and develops the French standard for liquid water flow meters calibration from 1g.h-1 to 36 t.h-1. The reference calibration facilities at LNE-CETIAT are historically based on the flying start and stop gravimetric method. Because of the specificity of micro-flow rates, two separated and dedicated calibration benches are used for flow rates from 1 g.h-1 to 10 kg.h-1 on one side, and from 8 kg.h-1 to 36 t.h-1 on the other side. Continuous improvement of the calibration capabilities pushes LNE-CETIAT to upgrade the existing methods toward a dynamic measurement of the reference flow rate, in the scope of EURAMET EMPIR "METROWAMET" JRP in which CETIAT is a partner of the consortium. After a short review of the state of the art and a description of the current LNE-CETIAT's, this paper will first present the development of a dynamic liquid flow generator required to ensure the measurand's representability. In a second part, the development of a dedicated and traceable measurement system, based on the existing gravimetric test rig, is described. Finally, the first feasibility test is presented and future developments are proposed.
Overview of measurements capabilities in radiation thermometry at CEM (Spain)
Authors: Martin M. J. , Mantilla J. M. , del Campo D.
Published: September 2019

CEM (Spanish National Institute of Metrology) is responsible for the maintenance and dissemination of the temperature national standards. Nowadays, the CEM Radiation Thermometry Laboratory disseminates and maintains the International Temperature Scale of 1990 (ITS-90) from the Ag fixed point (961.78 °C) to 2800 °C, using Ag or Cu fixed points as reference and standard radiation thermometers (RTs) working at a wavelength of 650 nm. CEM is also able to provide traceability to the new definition of the kelvin and to perform measurements of thermodynamic temperature from 400°C to 2800°C with different RTs (wavelengths of 650 nm, 900 nm and 1550 nm) using absolute and relative primary radiation thermometry. In addition the Radiation Thermometry laboratory performs calibration of RTs working in the usual infrared ranges (1 μm and 10 μm) from – 40°C to 1600°C.
A new set-up for the calibration of wood moisture meters
Authors: Fester Jakob , Kjeldsen Henrik , Østergaard Peter F. , Nielsen Jan
Published: September 2019

A set-up has been established to calibrate wood-moisture meters at Danish Technological Institute. The set-up is based on humidification of wood in an atmosphere with constant humidity, generated by saturated salt solutions. The measurements of the reference value are made by means of the loss-on-drying method and made traceable to a primary standard for moisture mass fraction established under the EMRP project METefnet in 2015. The facility was accredited by the Danish Accreditation Fund, DANAK, in 2018. In this paper, we report on the design of the calibration set-up, the uncertainty analysis and the validation by comparison to the primary facility.
Optical Phantom Development for Skin Measurement
Authors: ZHANG Jing , LIU Yuanjie , ROBIC Julie , NKENGNE Alex , YAN Hong , ZHANG Xing , Yun SOO Xiang
Published: September 2019

We have successfully developed and manufactured a three-layered scattering agent-embedded optical phantom in order to mimic the structural and optical properties of the human skin. Characterization is done for the optical phantom. The widths of the individual layers can be controlled within +/-10% of the designed thickness. The refractive indices, scattering and absorption coefficients are close to the human skin. The scattering agents in the optical phantom act as point sources which can be used to measure point spread function (PSF). Such a device can be useful for applications that require an accurate optical model for human skin evaluation such as Optical Coherence Tomography (OCT) and Reflectance Confocal Microscopy (RCM) in cosmetics and dermatological diagnostics.
Comparison of temperature dynamics of various thermal cycler calibration methods
Authors: Span Mary , Verblakt Marc , Hendrikx Tom
Published: September 2019

A multitude of testing laboratories, including medical, forensic, food, water and environmental testing laboratories, use thermal cycler equipment for Polymerase Chain Reaction (PCR) based DNA testing. PCR reactions are temperature critical and therefore these thermal cyclers require regular calibration to ensure correct functioning. Over time, a variety of calibration and verification methods have been published. Most of these methods are not traceable to the International Systems of Units (SI) and are connected to substantial measurement uncertainties, and therefore inapt for application in metrology. Physical temperature sensor based methods have found to be the most appropriate methods. These temperature sensor based methods can be categorized in in-tube and in-well methods. The in-tube methods measure temperature inside the PCR reaction tubes, which are placed in the wells of the thermal cycler heating block. The in-well methods measure temperature directly in the wells of the thermal cycler heating block. Both in-tube and in-well methods can be designed to be metrological traceable. However, the associated measurement uncertainty can vary substantially between in-tube and in-well methods. This paper compares the temperature dynamics of in-tube and in-well methods and discusses systematic and random errors which can contribute to the measurement uncertainty of both methods.
Preparation of hydrogen chloride in hydrogen standard gas mixtures for hydrogen purity requirements
Authors: Rojo Andrés , Santamaría Enrique
Published: September 2019

The hydrogen gas dispensed as fuel in refuelling stations for Fuel Cell Electric Vehicles (FCEV) should meet with purity requirements according to the actual normative. In this report we approach the preparation of hydrogen chloride/hydrogen (HCl/H2) standard gas mixtures, required to support the purity analysis of hydrogen fuel. The preparation of these mixtures was perform according to the gravimetric method, using dilution steps to reach the concentration level of 10 µmol/mol as the lowest. The mixtures were prepared in 5 L aluminium alloy cylinders with no internal treatment.
Improving fixed-point cell realization by modifying furnace heater shape
Authors: Lowe Dave , Wright Louise , Liller Chris
Published: September 2019

Recent changes to the SI make it possible to set up a primary temperature scale using established values for certain high-temperature fixed points. As the furnace used with the fixed points can itself have a significant impact on measurements, improving furnace temperature uniformity can help to reduce uncertainties. A thermal model was used to redesign heaters to reduce temperature gradients where the fixed-point cell is positioned in the furnace. A heater optimised for 1325 °C was compared to the standard one with a cobalt carbon high-temperature fixed-point cells, where the cell was installed in the middle, and also moved 10 mm to each end. The modified heater showed reduced melting range, improved plateau run-off and less sensitivity to fixed-point cell position. The improvements will reduce the uncertainties associated with this type of furnace.
Semantic Web Technologies for Data Curation and Provenance
Authors: Brown Clifford
Published: September 2019

The Reproducibility issue even if not a crisis, is still a major problem in the world of science and engineering. Within metrology, making measurements at the limits that science allows for, inevitably, factors not originally considered relevant can be very relevant. Who did the measurement? How exactly did they do it? Was a mistake made? Was the equipment working correctly? All these factors can influence the outputs from a measurement process. In this work we investigate the use of Semantic Web technologies as a strategic basis on which to capture provenance meta-data and the data curation processes that will lead to a better understanding of issues affecting reproducibility.
Improving reliability of power plant equipment due to measurement information redundancy
Authors: Sapozhnikova Kseniia , Baksheeva Iuliia , Taymanov Roald
Published: September 2019

Significant features of using the equipment installed at nuclear, hydraulic and thermal power plants are a multiyear cycle of continuous operation with minimum maintenance works and very high costs necessary to eliminate the consequences of possible crashes. Automatic checking of the state of the most important equipment units can become the optimal decision. In Russia, methods of building intelligent sensors and methods of intellectualization of multichannel measuring systems have been developed. Intellectualization of a measuring system enables to increase the reliability of equipment operation significantly. Examples are given.
Achieving precision measurements under non-standard environmental conditions
Authors: Tutsch Rainer , Sumin Dmitriy
Published: September 2019

Geometric measurements should be made at standard temperature 20°C, otherwise errors due to thermal expansion of workpieces and scales will occur. If measurements in serial production have to be made at different temperatures, DIN EN ISO 15530-3 describes a technique to correct the measurement error by referring to a calibrated reference workpiece. We have investigated this approach theoretically and experimentally and present some results.
The role of magnetic sensors in the hybridisation and electrification of vehicles
Authors: Kramb Marc , Slatter Rolf
Published: September 2019

Electrical currents need to be measured in a wide variety of different applications in the field of power electronics. However, the requirements for these measurement devices are becoming steadily more demanding regarding accuracy, size and especially bandwidth. In order to increase the power density of power electronics, as particularly important in the field of electromobility, there is a clear causal chain. Soft switching leads to higher efficiency and higher frequencies, which enable smaller dimensions for a given power output. Higher switching frequencies allow the size of magnetic components to be reduced significantly, resulting in more compact and lighter designs. This trend is now being reinforced by use of new wide bandgap semiconductor materials like silicon carbide (SiC) and gallium nitride (GaN), as their low on-resistances and low parasitic capacitances reduce switching losses. Conventional current sensor solutions, e.g. hallor shunt based sensors exhibit a limited bandwidth, typically less than 250 kHz. Other current sensors, like those based on the Rogowski-Coil, are capable of highly dynamic current measurement, but are significantly more expensive, larger and hence not suitable for large series applications. Furthermore, Rogowski-Coils are only capable of measuring alternating currents (AC), which prevents their use in applications where DC currents must also be measured. In order to meet the above mentioned requirements, magnetoresistive (MR) current sensors are ideally suited due to the fact that the bandwidth of the magnetoresistive effect extends up into the GHz-range. This paper describes the principle of operation and main performance characteristics of highly integrated MR current sensors and describes their benefits compared to other types of current sensor, in particular with regard to applications in the hybridisation and electrification of vehicles.
Precision of the Residual Stress determined by X-ray Diffraction: Summery and Limits
Authors: Mueller Eckehard
Published: September 2019

Today components specially for passenger cars are weight optimized. Often it is done by mechanical surface treatments. Therefore, the amount of compressive residual stress induced by the treatment must be known. The measurement is very often done by x-ray diffraction. But how precise can you determine (and not directly measured) the amount? A big question is the calibration of the equipment. A specimen must be designed and calibrated by round robin test, because no measurement standard is available.
Novel method for the realization of small differential pressures between 1 Pa and 1 kPa
Authors: Sander Christian , Harich Falko , Förderer Martin , Sander Eugen
Published: September 2019

This paper reports a novel method for the realization of small differential pressures in the range of 1 Pa and 1 kPa by using a precision wind tunnel with Laser Doppler Anemometer (LDA) and a Prandtl tube. The LDA system measures the wind speed of the precisely controlled wind tunnel and provides traceability to SI. A Prandtl tube immersed into the wind tunnel, relates the well-controlled airflow speed to the pressure difference of total pressure and static pressure at the point of measurement. Experiments have been performed in the range between 0.5 and 60 m/s air velocity corresponding to about 150 mPa and 2.2 kPa. The measurement uncertainty of the generated differential pressures between 1 Pa and 1 kPa are calculated to be around 0.8% (k = 2).
Research on an alternative LS2P microphone based on a new reciprocity calibration system
Authors: Enge Maria , Hof Christian , Barrera-Figueroa Salvador
Published: September 2019

The microphone calibration by the reciprocity technique specified in IEC 61094-2 is used to determine the sensitivity of laboratory standard microphones according to the IEC 61094-1 with the smallest measurement uncertainty for the use as reference microphones. So far, laboratory standard microphones by the manufacturer Brüel & Kjær (Type 4160 and Type 4180) are almost exclusively used as laboratory reference microphones. In order to create an alternative, the initiative has been taken to examine the usability of the ½-inch laboratory microphones G.R.A.S. 40AU-1. Studies were launched to check the microphone parameters, the stability and the reciprocity of the microphones as well as the compatibility with microphones by Brüel & Kjær. Basis for the investigation was a new validated reciprocity calibration system. The realization of the system and the research results are presented and discussed. Additionally, results of comparison measurements with national metrology institutes are shown in shortened fashion.
New strain gauge-based torque reference chain offering smallest measurement uncertainties
Authors: Schäfer André
Published: September 2019

New measurement approaches for mechanical quantities based on strain gauge technology offer one feature above all else: the possibility to realize smallest measurement uncertainties. This is particularly important for metrological infrastructure, i.e. realization of metrological traceability chain to support applications in aerospace or in automotive industry. Achievements toward smaller measurement uncertainties are shown by realization of a novel torque reference sensor TN with improved usability for inter-laboratory comparisons in combination with a surprisingly compact precision amplifier called Quantum MX238B.
Influences of sensor protective coating on laser energy calibration results
Authors: Kılınç T. Oytun , Sönmez K. Berk , Yüksel İ. Ahmet , Ön Aktan Sinem
Published: September 2019

Improving laser energy measurement is a challenging task. Pyroelectric crystalline energy sensors used in laser energy measurements have a working principle that absorbs the heat of incoming light. Therefore, it is very important to measure the heat transfer in the incoming laser beam with maximum efficiency. The condition of the black sensor coating used to maximize this efficiency plays a leading role in the measurements. By means of laser energy sensor calibration measuring setup, the energy of the pulsed laser source at a wavelength of 1064 nm and a frequency of 20 Hz was measured with damaged and undamaged black sensor coatings. The present study may provide useful guidance into the understanding of black coatings of the detectors to use in laser energy calibrations.
Long-term Outcome of Subacute Thyroiditis
Authors: Görges Julia , Ulrich Jan , Keck Christoph , Müller-Wieland Dirk , Diederich Sven , Janssen Onno E.
Published: September 2019

Background Subacute thyroiditis (SAT) is a rare inflammatory disease that presents diagnostic challenges. The underlying pathophysiology and prediction of outcomes are elusive. We investigated the long-term follow-up of SAT for up to 30 years and determined predictors for later hypothyroidism.

Methods SAT outcome data from 127 patients (age: 47.6 ± 11.0 yrs., BMI: 24.7±4.8 kg/m²) were analyzed retrospectively. Patients with pre-existing and known causes of hypothyroidism unrelated to SAT were excluded. We also excluded patients without an accelerated erythrocyte sedimentation rate. SAT outcome parameters included anterior neck pain or tenderness of the thyroid, inflammation markers, hypoechoic areas in thyroid ultrasound, hyperthyroidism, fine-needle aspiration, and thyroid scan. Pre-treatment TSH-levels, gender, age, ultrasound findings, anti-thyroid antibodies and markers of inflammation were considered as possible predictors of SAT outcome.

Results More than 26.8% of SAT patients developed permanent hypothyroidism within 3 years of treatment. The patient groups later developing hypothyroidism did not differ in age, BMI, pre-treatment TSH levels or initial dosage of prednisolone treatment. However, high cumulative doses of prednisolone were associated with a higher prevalence of hypothyroidism. Also, women were more likely to develop hypothyroidism (OR: 3.18 (95% CI: 1.14–8.65); p=0.0176).

Conclusions Our study suggests that one-quarter of patients with SAT develop hypothyroidism in the long-term. Hypothyroidism was predicted by high cumulative doses of prednisolone treatment and female gender. The reported lower prevalence of hypothyroidism in other countries may represent the faster establishment of diagnosis, different treatment protocols, or lower susceptibility to loss of thyroid function. Swift establishment of the diagnosis and rapid tapering of steroids may result in a higher proportion of patients with euthyroidism.