This article displays how the photometry laboratory of the Portuguese Institute for Quality complies with the measurement traceability and method validation, the technical requirements 5.4 and 5.6 of the ISO/IEC 17025. After the presentation of the existing means and the way the metrological traceability is obtained, a short introduction to the internal validation of the measurement method is displayed for the luminous intensity, the illuminance and the illuminance responsivity.

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.

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.

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.

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 Technical Center of Industries of Screw-machining (Ctdec) in France. Its first step is the organization of the different machining operations, in setup steps, themselves subdivided into measuring steps. The second step consists in determining the manufacturing dimensions to measure at the end of each measuring step. Finally, the third step consists in linking the manufacturing dimensions to both the correctors and the tool-dimensions, in the aim of calculating the corrections that have to be done in function of the deviations measured on the manufacturing dimensions. With this method, the steering of an industrial workpiece is performed with two steering parts instead of ten before.

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.