The international standard, ISO/IEC 17025 was developed to determine technical competenceand to evaluate laboratories throughout the world. Accreditation bodies playing a vitalrole are increasingly using proficiency testing methodology as a tool to ensure thecredibility of their accreditation programs. The successful completion of a well-designedproficiency test can validate the measurement method and uncertainty budgets of a testinglaboratory. Additionally, proficiency tests can provide a good indication about thequality of the test results. An important part of inter-laboratory comparisons andproficiency testing is the determination of the associated error analyses which arefocused on uncertainty values. This paper presents the implementation of proficiency testsusing inter-laboratory methodology among five different acoustic laboratories. These testswere carried out on 5.27 KWCooling standard unitary air conditioner, A/C, suchas through-wall or split room standard A/C units, for the assessment of Housing &Building National Centre acoustic laboratory. Analyses of results show a good agreementfor En-Value among the selected laboratorieswhen compared with the lowest uncertainty as stated by proficiency tests standards.

This article displays how the photometry laboratory of the Portuguese Institute forQuality complies with the measurement traceability and method validation, the technicalrequirements 5.4 and 5.6 of the ISO/IEC 17025. After the presentation of the existingmeans and the way the metrological traceability is obtained, a short introduction to theinternal validation of the measurement method is displayed for the luminous intensity, theilluminance and the illuminance responsivity.

In this work we present an experimental investigation of the employment usage application of the vertical pixel binning (PB) option for PIV (particle image velocimetry) measurements. The PB option increases the speed of a CCD, at the cost of loosing spatial resolution. Consequently, it is expected that PB will positively impact the dynamic velocity range of the PIV measurements. In order to show the benefit of the CCD PB option in PIV measurements, we have carried out series of microPIV experiments on laminar flows, seeded with 1 μm fluorescent polystyrene microparticles and passing through a 200 μm × 200 μm × 50000μm microchannel. The flow images were recorded at normal, 2 × 1, and 3 × 1 vertical PB modes of a monochrome CCD camera. The experimentally obtained velocity profiles were calculated using the ensemble-averaged cross-correlation method and Gaussian sup-pixel interpolation and then compared with theoretically calculated velocity profiles. We found that the error introduced by the PB option did not exceed the inherent uncertainty of the PIV system used. For a particular PIV system CCD camera, using the PB option allowed an increase in the dynamic velocity range of a PIV system by more than a factor of two, without extra investments.

Traceable measurements are a mandate for the reliability of test results. Although periodic calibration activities ensure traceability, in between verifications are essential to maintain the consistency of results. In analytical laboratories, electronic balances are widely used for quantity estimations. Owing to the inherent instability problems associated with semiconductor strain gauges and performance degradation on aging, they need to be regularly controlled using verification mass. But traceable and calibrated masses are expensive for routine use in laboratories. A mass set is designed, prepared in-house and mass values with uncertainty are assigned to undergo such verification. Steps employed to assign the mass values based on the principle of inter laboratory comparison (ILC) are reported. Reference value and corresponding uncertainty estimations are determined by performing an ILC in five different laboratories. The measurement results with uncertainty from each laboratory were received for individual masses. These results were analyzed for consistency and the values along with the weighted uncertainties were assigned.

The dissemination of traceability to the International Temperature Scale of 1990 (ITS-90) through comparison calibration of thermocouples, is playing an important role in metrology institutes, secondary laboratories and industrial measurements. The previous studies of the Pt/Pd thermocouples at NIS-Egypt, shows promise of achieving significant improvements uncertainty of temperature measurements up to 960 °C. In this paper we describe the uncertainty assessment on the measurements of the calibration of Pt/Pd thermocouples at fixed point cells up to the freezing point of copper and by the comparison technique following a defined heat treatment at 1100 °C. All the measurements on Pt/Pd thermocouples were carried out using NIS facilities.

A Proficiency Test Scheme (PTS) for histamine analysis in fishery products using the Lerke and Bell (1976) fluorometric method was conducted in 26 different Moroccan laboratories. The goal of this PTS was to assess the abilities of a network of seven government laboratories and 19 laboratories performing auto-controls on fish processing units in Morocco. The samples used in the PTS were prepared from canned ground mackerel flesh, to which was added two significant concentrations (levels 1 and 2) of histamine. The homogeneity of the PTS samples was verified by a repeatability test and their stability by an intermediate fidelity test. The Cochran test was used to eradicate anomalous scattering and the Grubbs test to eradicate the anomalous averages observed in the results of the participating laboratories. The average and the usual deviations determined for levels 1 and 2 were used to calculate the Z-scores. For level 1 therefore, 23 out of 26 laboratories had satisfactory PTS results, and for level 2, 21 out of 26 laboratories had satisfactory PTS results. An analysis of the PTS samples using the HPLC reference method gave similar results for levels 1 and 2.

The behaviour of piston-cylinder operated pressure balances is characterized by thedistortion coefficient λ and zero-pressure effective areaA0 which model the variation of a pressure balance’s area interms of the applied pressure. This paper determines the uncertainties inλ and A0 when utilizing the method ofcross-floating with another pressure balance standard whose parameters and associateduncertainties are known. A limitation that is frequently encountered in many attempts ofthe uncertainty analysis for a pressure balance is that no readily accessible uncertaintyquantification framework for the distortion coefficient is present. As a result theuncertainty in a pressure balance’s area at elevated applied pressures is typicallyunderestimated in the absence of this uncertainty information. We firstly review theuncertainty formulation for a pressure balance generated pressure involving correlationeffects in terms of an implicit multivariate matrix equation approach and then utilizingthe resulting solution present the methodology to consistently perform the uncertaintyanalysis for λ and A0.

This paper proposes a bootstrap approach to determine the measurement uncertainty of measurement devices with unknown measurement equation (in this work, a structured light projection system is applied for the measurement of pull broaches) by use of workpieces that are calibrated by a coordinate measuring machine (CMM). The obtained uncertainty is used to perform a conformance assessment of the initial measurement process according to ISO 14253-1 and VDA 5.

This paper describes a new approach for the analysis of signals containing fluctuating harmonics. It is based on the Fourier transform, using windowing to reduce the error arising from analysing the signal over a non integer number of signal periods and an iterative process intended to estimate and correct the errors. Some simulations have been performed to prove the efficiency of the method and showed that the final error arising from the computation generally ranges between a few parts in 1010 and a few parts in 1015.

We have experimentally investigated the MTF of a scientific grade CCD, especially considering its behavior induced by different laser wavelengths (from 470 nm to 633 nm) and varying number of total charge transfers. The MTF measurements were performed using laser speckles and utilizing the single-slit method. The MTF of the sensor was examined from zero to the Nyquist frequency. The results obtained at different wavelengths were compared. It was shown that the spectral behavior of the MTF is negligibly small; moreover the small variation is observed at the high frequency region. It was also observed that the variation of the total number of charge transfers, adjusted by size and location of the region of interest for readout pattern, is within the intrinsic error of the single-slit aperture laser speckle method.

This paper presents and compares different approaches currently used to assess surface anomalies identified on a product. The common point between these methods is that they are based on a document presented in the form of a table, which is to help the inspector to assess the anomaly detected in a repeatable and reproducible way. We will present three types of table: criteria/level table, tree-like presentation table and an indexed table. As each of these tables presents certain limits when applied to the inspection of a product surface, we will describe the table proposed in order to help the inspector determine the intensity to attribute to the identified anomaly.

Medical measurements are present in the everyday life of people and are fundamental processes in prevention, diagnosis and treatment of disease. Therefore, a growing interest lies in the role of metrological decisions and conformity assessment, namely where measurements are in support of health. This paper focuses on the use of medical devices looking to enhance its metrological traceability, highlighting the specific role of metrology in the field of health care and the impact of legal control in the framework of the medical devices regulation with a measuring function. It is proposed a new regulatory approach for medical devices in use, facing the convergence between European policy enforcement and Metrological regulations.

Copilot Pro® is a method for the initial and regular machine-tools setup,developed by the Symme laboratory of the Savoy University and by the TechnicalCenter of Industries of Screw-machining (Ctdec) in France. Its first step is theorganization of the different machining operations, in setup steps, themselves subdividedinto measuring steps. The second step consists in determining the manufacturing dimensionsto measure at the end of each measuring step. Finally, the third step consists in linkingthe manufacturing dimensions to both the correctors and the tool-dimensions, in the aim ofcalculating the corrections that have to be done in function of the deviations measured onthe manufacturing dimensions. With this method, the steering of an industrial workpiece isperformed with two steering parts instead of ten before.

The accuracy of thermal conductivity measurements is even more requested for materialscharacterization in energy-efficient buildings field. ENEA-UTTMATF and CertiMaC researchgroup, as national institute and private laboratory respectively, cooperate in developmentof new measurement and analysis methods applied to buildings materials and theirperformances. For what concerns this kind of measurements, an Heat Flow-meter Transducer(HFT) is used. In order to give to both customers and other research institutes involvedin the same field (e.g. International Comparison or International Round Robin Tests) themost exhaustive evaluation of the tested material thermal conductivity, a completeuncertainty analysis is implemented on the HFT measures. This uncertainty analysis,developed accordingly to the international standards and with the contribution of INRiMInstitute, is described in this paper.

Process performance can be analyzed by using process capability indices (PCIs), which are summary statistics to depict the process location and dispersion successfully. In some cases, quality characteristic and target are not precise numbers and they are expressed in fuzzy terms, so that the classical capability indices cannot be applied. In this paper we obtain a confidence interval for inertial capability index Cpi (defined by [Pillet, TQM Mag. 16, 202–209 (2004)]) based on fuzzy data and propose a membership function for it.

The weighted inertial piloting of processes presented in this paper is a break-away in terms of the quality of machined mechanical workpieces compared to the traditional piloting carried out by machine setters. However, sometimes one has a stability problem during the piloting phase due to over adjustment. We propose to study the causes of this instability and to develop an approach in order to correct the problems. Once we have reminded ourselves of the basics of weighted inertial tolerancing, we will propose an approach to identify the most probable decentring. The applications of the concepts discussed in this article were tested over a period of two months. The results are very convincing, especially with the elimination of the phenomenon previously observed in identical conditions.

Most research works related to process capability indices assume no gauge measurement errors. However, such an assumption inadequately reflects real situations even when advanced measuring instruments are employed. If we do not take into account these errors, conclusions drawn from process capability are therefore unreliable. In this paper we study the sampling distribution of capability indices Cp''(u,v) in the presence of measurements errors, and when small subsamples data are collected from past “in-control”. We show that using a critical value without taking into account these errors, severely underestimates the α-risk which causes a less accurate testing capacity. To improve the results we suggest the use of an adjusted critical value, and we give a Maple program to get it. An example in a nougat manufactory is presented to illustrate this approach.