In June 2009, the Laboratory in hydrology of Nancy (Ansès-LHN, Nancy) conducted anexploratory inter-laboratory proficiency tests (ILT) test in collaboration with theAQUAREF network to identify laboratory practices and estimate inter-laboratory uncertaintyfor the compounds under study. There were a total of 12 compounds belonging to sixfamilies (hormones, antibiotics, non-steroidal anti-inflammatory drugs, beta blockers,antipsychotics and others) including one compound used in veterinary medicine. It was thefirst ILT conducted in France on water intended for human consumption. Thirty-onelaboratories participated, 4 of which were located abroad.

This paper reports work carried out to determine the influence of the Pyramidal indenter geometrical errors and tolerances on the accuracy of Vickers hardness measurements. The angle between the opposite faces and line of conjunction of nine indenters were measured by the optical comparator. The influence of the indenter geometry on the hardness accuracy is investigated. Three calibrated reference hardness test blocks were used to check the Vickers hardness test using the nine selected indenters. The results show that the geometrical error of the indenters (specially the angles) considerably affects the accuracy of the hardness measurement. Finite element analysis of the indentation process into metallic test pieces was conducted. Comparison of the experimental results with the numerical findings was discussed. Errors in the experimental values are correlated with measured tolerances in the angles between faces.

Optimum safety and reliability can be achieved by coordinating an interlaboratoryproficiency testing among different laboratories. Testing laboratories need to verifytheir test procedures and testing capability for reliable results. In this study,equivalent samples are prepared by cellulose based transformed board material used intransformers as electrical isolation material. Randomly selected test samples havingspecified dimensions are sent to the participant laboratories. Then they are tested andresults are analyzed according to previously defined parameters. Each laboratory appliedtensile and flexural tests on the samples according to procedures given in IEC 60641-2,2004 and IEC 60763-2, 2007 standards respectively. Test results are evaluated according tosame procedures explained in related standards by the participant laboratories. TUBITAKUME Material Testing Laboratory being the pilot laboratory collected to the all evaluatedresults including associated measurement uncertainties. Then the collected resultsevaluated according to ISO 17043, 2010 are reported by each laboratory as a part of theproficiency test report. Z-scores of the participant laboratories are presented.

Nine european national metrology institutes (NMIs) are collaborating in a new project funded by the european metrology research programme (EMRP) to establish traceable dynamic measurement of the mechanical quantities force, pressure, and torque. The aim of this joint research project (JRP) is to develop appropriate calibration methods, mathematical models, and uncertainty evaluation. The duration of the project is 3 years for a global amount of €3.6 million. It began in September 2011.

We describe an efficient continuous-wave diode-pumped Nd:YLiF4 laseroscillating on the σ-polarized4F3/2-4I13/2transition at λω = 1312 nm. With a simplelinear cavity laser, we reached an intracavity power of 310 W at λ = 1312nm for 16 W of absorbed pump power(λp ~ 806 nm). A 0.25 W of tunableradiation (λ2ω = 656−658 nm) was obtainedby intracavity second-harmonic generation (SHG) with a 5 × 5 × 7mm3β-BaB2O4 crystal. Up to 10 mW oftunable single-frequency operation was observed using a 200 μm thin fusedsilica intracavity solid etalon. The optimal waist for a maximum conversion efficiency hasbeen calculated theoretically using Boyd and Kleiman model. For the 1312–656 nm SHG, wefound a walk-off parameter B = 8.99 and an optimal waist of 25μm. Comparing to the experimental measurement of the optimal waist, wefound a relative discrepancy of 2.84 × 10-2. This laser is dedicated to thespectroscopic study of silver atoms trapped in a buffer-gas-free paraffin coated Pyrexcell that will be used in a compact atomic optical clock.

Today’s global economy obliges manufacturers to produce their products in high quality with cheaper cost. Thus, manufacturers must develop their products applying tests to get better performance and higher quality before distributing them to the competitive market. In order to produce long working life of transformer reactors without losing their performance, different tests including axial and flexural testing are applied on the cellulose based laminated board material used in production. During development of laminated board material, test results should be known very well and the measurement uncertainty of tensile tests should be calculated taking into account all parameters. In this study, effective parameters on the quality of tensile testing causing an increase on the measurement uncertainty are investigated. Tensile strength and elongation test of laminated board material were carried out according to IEC 60641-2 and the uncertainty contributions based on experimental results were calculated. The results and impact of the uncertainty parameters are presented in detail.

This paper is devoted to the study and implementation of real-time techniques for the estimation of time-varying, contingently correlated quantities, and relevant uncertainty. An estimation algorithm based on a metrological customization of the Kalman filtering technique is presented, starting from a Bayesian approach. Moreover, a fuzzy-logic routine for real-time treatment of possible outliers is incorporated in the overall software procedure. The system applicability is demonstrated by results of simulations performed on dimensional measurement models.

The Guide to the expression of measurement uncertainty, (GUM, JCGM 100)and its Supplement 1: propagation of distributions by a Monte Carlomethod, (GUMS1, JCGM 101) are two of the most widely used documents concerningmeasurement uncertainty evaluation in metrology. Both documents describe three phases (a)the construction of a measurement model, (b) the assignment of probability distributionsto quantities, and (c) a computational phase that specifies the distribution for thequantity of interest, the measurand. The two approaches described in these two documentsagree in the first two phases but employ different computational approaches, with the GUMusing linearisations to simplify the calculations. Recent years have seen an increasinginterest in using Bayesian approaches to evaluating measurement uncertainty. The Bayesianapproach in general differs in the assignment of the probability distributions and itscomputational phase usually requires Markov chain Monte Carlo (MCMC) approaches. In thispaper, we summarise the three approaches to evaluating measurement uncertainty and showhow we can regard the GUM and GUMS1 as providing approximate solutions to the Bayesianapproach. These approximations can be used to design effective MCMC algorithms.

Calibration of volumetric proving tanks can be done using different methods. For thecalibration of large proving tanks the master meter method can be used as a goodalternative to the volumetric transfer method or the gravimetric method. When the mastermeter method is used in most cases a positive displacement meter is used. A better optionis to make use a Coriolis mass flow meter as the master meter. Test data is presented of acalibration of a proving tank with a nominal volume of 500 L. Small repeatability figurescan be obtained of consecutive calibration runs with a Coriolis mass flow meter. Also thelinearity of the meter factor curve of the Coriolis mass flow meter makes this a betteroption for the master meter method.

This paper presents the evaluation of the uncertainty for the length measurement of gauge blocks by optical interferometry. In order to improve the gauge block calibration method and to decrease measurement uncertainty the old Zeiss-Kösters gauge block interferometer has been modified and improved by DMDM (Directorate of Measures and Precious Metals of Serbia). The main modification of the interferometer covers introduction of two laser sources, as new wavelength standards, as well as new hardware system and interferometer software, developed to completely automate the calibration process. The validation of the new measurement procedure details the uncertainty budget. The measurement method and model equation, which serves as the basis for the uncertainty evaluation is described. The uncertainty evaluation is performed in accordance with the document JCGM 100:2008-Evaluation of measurement data – Guide to the expression of uncertainty in measurement (GUM).

This paper describes an approach to generating reference data sets to evaluate the performance of algorithms used in coordinate metrology for form and geometric tolerance assessment. The approach starts with the reference results, e.g., the solution feature parameter values, and then determines the coordinate data. In this way, the expensive development of reference software is avoided. In this paper we consider the generation of reference data associated with determining the best-fit surface according to the least squares (Gaussian) and Chebyshev criteria.

A number of calibration techniques are used in Radio Frequency (RF) calibration for power, attenuation and impedance parameters. Mismatch uncertainty plays a major role in these measurements and in estimation of combined uncertainty according to ISO/IEC 17025:2005 and GUM document. Formulas to evaluate the mismatch uncertainty in terms of reflection coefficient, voltage standing wave ratio and scattering parameters have been evaluated earlier and are being used in RF calibration. The present paper summarizes the mismatch formulas previously studied and the modified ones suitable to the measurement system and techniques available today. For power and attenuation calibration in the particular frequency range, an establishment of traceability for one-port measurement in the same frequency range is required. The methods to reduce and control this uncertainty component and their limitations are also discussed forbest measurements practices in the calibration laboratories.

A new comparison system has been constructed for the calibration of capsule-type standardplatinum resistance thermometers (CSPRTs) below 273.16 K at the National Institute ofStandards (NIS-Egypt). The system can compare two CSPRTs at once. A gold plated comparisonblock, in which CSPRTs are mounted for calibration, is made from oxygen-freehigh-conductivity copper. A description of the system and the comparison block along withthe comparison method is given. The standard uncertainty related to the temperaturecontrol of the system is estimated to be 0.04 mK. The calibrated values for CSPRTs andobtained using the comparison system are in good agreement with those obtained by thedirect realization of the low temperature fixed points of the ITS-90 within the combinedstandard uncertainty.

The Statistical Feed-Forward Control Model (SFFCM) relies on a sequence of specification adjustments made on subsets of a population to counter the influence of the long time component of the variation. The difficulty strives in finding a proper estimate for the measure of the central tendency of each subset to minimize the number of the required adjustments. By means of simulating the assembly of two components having high dimensional variation, forty experiments were designed to compare the individual influence of different factors such as the number of adjustments, the sampling strategy and two measures of central tendency: the sample mean and the cumulative de-noised average. Simulation results showed that, regardless of the sampling strategy but keeping the inspection rate at 20%, the use of the cumulative de-noised average instead of the sample mean made possible to reduce the number of adjustments by 20%. Thus, while the shift mean of the resulting assembly was decreased by 90%; the standard deviation was reduced by 15%. Hence, the selection of a proper central tendency measure is crucial when modeling the long time variation. The cumulative de-noised average proved to be a valid alternative.

Laser trackers are becoming the tool of choice for large volume dimensional metrologyapplications such as the measurement of aerospace assemblies, power plant structures,civil engineering structures and terrestrial transportation vehicles. A laser tracker is aportable coordinate measuring system that tracks a moving target reflector and measuresthe position of the target in spherical coordinates (r,θ, φ). The metrological performance of a laser trackeris influenced by many factors including: compensation for atmospheric effects, thermalexpansion of the instrument and its mount, thermal distortion of the workpiece or artefactbeing measured, the wavelength of the laser radiation, the internal alignment of thegimbal axes and the linearity and alignment of the internal angular measuring scales. Themost important of these potential error sources, which fundamentally limit the achievableuncertainty, are the internal mechanical and optical alignments and the quality andalignment of the angular scales. Several national and international standards exist or arein the process of being developed for performance verification of laser trackers. ASMEB89.4.19-2006 is one of the established standards used to verify the performance of lasertrackers. The main test relies on measuring a known reference length in a variety ofconfigurations and ranges and comparison of the observed error (laser tracker measuredlength minus reference length) with the specified maximum permissible error (MPE) definedby the manufacturer. The establishment of an ASME B89.4.19 laser tracker verificationfacility at NPL is introduced. We highlight the importance of tracker verification anddiscuss the error sources, which contribute to the tracker measurement uncertainty. Someinitial results obtained using this new facility are presented.

The Guide to the expression of uncertainty in measurement (GUM) requires, “that the results of a measurement have been corrected for all recognised significant systematic effects and that every effort has been made to identify such effects”, before the issue of evaluating their uncertainty is tackled. In addition, the GUM also requires that a model is used, expressing the functional dependence of the measurand on identified input quantities. The paper discusses the inter-relations between the so-defined two sets of influence quantities and proposes to unify their treatment.

Quality of transformer oil plays vital role in the performance of transformer in electrical appliances. Measurement uncertainty is a general concept associated with any measurement and can be used in professional decision processes as well as judging attributes in many domains, both theoretical and experimental. As the tolerances applied in industrial production become more demanding, the role of measurement uncertainty becomes more important when assessing conformity to these tolerances. Measurement uncertainty plays a central role in quality assessment and quality standards. In an effort to meet national, international and commercial accreditation requirements, users of transformer oil testing machines must establish adequate methods of determining calibration and test measurement uncertainties. Determining measurement uncertainty for transformer oil testing equipments and test data can be a very complex process. Many factors affect the uncertainty of test data produced by testing machines. In this paper, the concepts associated with the procedure for estimation of uncertainty is discussed and the application of these for the determination of uncertainty in transformer oil testing equipments in government testing labs is illustrated. The objective of this study is to develop a methodology for determining the result of measurement concerning electrical properties of transformer oil and their respective uncertainties.

Three dimensional coordinate metrology is a firmly established technique in industry.Scanning technology is now widely used in coordinate metrology and is increasingly usedfor the measurement of small features. This paper presents a new real shape approach toclosest point inspection involutes curve of gear tooth by coordinate measuring machinery(CMM). This method aims to select the most likely contact point for each successive arc byapplying geometrical criteria and a fuzzy logic estimator. This method is particularly,but not exclusively, suitable for the metrology of features with small radii as well asmetrological discontinuities. It does not require obtaining the normal vectortraditionally used for probe tip correction. Elapsed time is 144.09 s. Tests have beendone on limps of machine tool speed (pinion type cutter), which is highly applied in ourcountry.

The phase error in a high quality accelerometer was investigated on the basis of systematic experiments on a prototype platform permitting controlled vertical harmonic oscillations. The recordings of an accelerometer and of an ultra-high frequency GPS fixed on this platform were compared with those of a LVDT transducer, controlling the platform movement. All sensors were supported by independent GPS timing. The output of this study is that the recordings of accelerometers are characterized by a random phase error, which, however, decreases with the increase of the oscillation frequency, as dictated from the laws of mechanics. Such errors are important given the increasing use of combinations of accelerometers with various sensors for a wide range of applications. A simple method for the correction of such errors is proposed.