Evaluation of geometric deviations for the purpose of determining compliance with specified form tolerances requires the acquisition of numerous measured data points and extensive computation to accurately characterize the inspected part’s geometry. If there are not enough data points measured or when the measured points are not distributed properly on the measured surface a high level of uncertainty in characterizing the inspected part’s geometry can be expected. However, increasing the number of data point also significantly increases the computational time and also increases computational uncertainty by adding to instability of the optimization process required to find the minimum deviation zone. Selections of number and location of the measured date points need to be performed by understanding the significance of these two sources of uncertainties. This paper discussed the effect of sampling procedure on uncertainty and precision of flatness inspection.

The solid flow in air-catalyst in circulating fluidized bed was simulated with CFD model to obtain axial and radial distribution. Therefore, project parameters were confirmed and steady state operation condition was improved. Solid holds up axial end radial profiles simulation and comparison with gamma transmission measurements are in a good agreement. The transmission signal from an 241Am radioactive source was evaluated in NaI(Tl) detector coupled to multichannel analyzer. This non intrusive measuring set up is installed at riser of a cold pilot unit to determine parameters of FCC catalyst flow at several concentrations. Mass flow rate calculated by combining solid hold up and solid phase velocity measurements was compared with catalyst inlet measured at down-comer. Evaluation in each measured parameter shows that a relative combined uncertainty of 6% in a 95% interval was estimated. Uncertainty analysis took into account a significant correlation in scan riser transmission measurements. An Eulerian approach of CFD model incorporating the kinetic theory of granular flow was adopted to describe the gas–solid two-phase flows in a multizone circulating reactor. Instantaneous and local gas-particle velocity, void fraction and turbulent parameters were obtained and results are shown in 2 D and 3D graphics.

In this paper, we describe techniques for evaluating the uncertainties associated with the assessment of form error, i.e., the departure from ideal geometry of a manufactured part, in coordinate metrology. The techniques take into account measurement uncertainty, sampling effects due to the fact that the form error is determined from a finite set of coordinate data points, and the spatial correlation of the form errors. The techniques are designed to be practical, without the need for complex computation.

This paper describes the methodology of the compatibility criteriaEn and the methodology of repeatabilityand reproducibility (R&R) throught the average and range method. With this paperwe will use the methodology R&R for the evaluation of the compatibility criteriabetween the staff of the laboratories, where independent measurements are not insured.

In order to determine mechanical properties of materials various kind of tests can be applied by means of using their tensile strength, lower yield stress, proof stress, impact strength, Brinell, Rockwell and surface hardness, elongation after fracture properties. Among these tests, three point flexural testing method has some advantages such as easy preparation (production) of samples and no gripping problems comparing to tension test. Flexural tests results should be obtained accurately to provide expected testing performance. The measurement uncertainty of flexural tests should be calculated by conducting all effective uncertainty parameters during the test procedure. In this study, the measurement uncertainty of the flexural test of ABS (Acrylonitrile Butadiene Styrene) material was investigated, which is widely used as industrial plastic material in many applications.

In mechanical design, geometrical specifications and dimensional tolerances are commonly used to avoid final product malfunction and to allow for assembly integration. Geometric specification usage, in particular, has many manufacturing and durability implications, the feasibility of their measurement and verification, however, is often neglected and the influence of measurement uncertainty in their evaluation underestimated. Often geometrical specifications are defined without considering measurement uncertainties, or measurability at all: it is not uncommon to find approved specifications prescribing unverifiable geometry, or dimension tolerances that exceed state-of-art measurements. This article explores the case study of orthogonality between a circular hole and the plane on which it is drilled, evaluated using a Coordinate Measuring Machine. Such specification is defined, according to ISO 14253, as the angle between the plane normal and cylinder axis. Uncertainty of points coordinates obtained can, however small, play a key role in the final evaluation of orthogonality: if the specified tolerance is thigh enough it is also possible to have misalignment uncertainty higher than the tolerance itself. The authors propose the results of a mathematical and numerical model, meant to help the designer to define specification to assess the relationship between cylinder-plane misalignment measurability, CMM uncertainty and features dimensions.

In the context of measurement and of the definition of measurement units, a problem well known in computing science, the inherent propagation and accumulation of rounding errors throughout the intermediate steps of numerical calculation, is discussed in this paper, with some issues in notation, namely of integer numbers.

Understanding the ageing of materials for electronic application is a complex challenge, in particular for composite material as electrically conductive adhesive consisting of a nonconductive polymer binder and conductive filler particles. This research involves a large amount of parameters related to both operating conditions and material structure, which act together. Accelerated testing, with the aim to consume rapidly lifetime without inducing incorrect failure mechanisms, is difficult to optimize and its modelling to describe the ageing process is a challenge. To reach this aim could be interesting for the characterization of the material but above all for the general validity of the proposed methodology.

The Guide to the Expression of Uncertainty in Measurement describes a method of evaluating measurement uncertainty that involves attributing an underlying variance to each component of the total measurement error. Assessment of such a variance by statistical methods is known as Type A evaluation of uncertainty, while assessment by any other means is known as Type B evaluation. The involvement of degrees of freedom with Type A evaluation is in accordance with statistical theory. However, the use of “degrees of freedom” with Type B evaluation is an idea primarily developed for practicality, and might be improved upon. That idea ignores the fact that the underlying distribution of the corresponding error will often be assumed to be blunter than normal, as with a uniform distribution, and it can lead to underestimation of the total error variance. Consequently, an alternative concept for Type B evaluation is presented. The resulting analysis fits easily with the use of degrees of freedom in Type A evaluation and leads to an overall method of evaluation that often permits the proper quotation of shorter uncertainty intervals.