Analysis of measurement uncertainty sources in the casting process

The concepts used in metrology are increasingly part of the productive process of metallurgical companies, considering the globalization of the world market. The interpretation of metrological concepts and their application in decision-making is still a challenge for the industry, especially for the measurement uncertainty calculation. Industries in the casting area are in great need of skilled labor both in relation to the productive process and engineering, as well as in metrology, highlighting the interdisciplinary of the concepts studied in the technical or baccalaureate courses. Therefore, the main objective of this work is to perform a brief literature review of publications made using the value of uncertainty of measurement within the production process of foundries. The results show that there is a potential research in the field, to which it relates the values of measurement uncertainty and fused components.

Uncertainty of measurement and conformity assessment

Knowledge of the measurement uncertainty of test results is fundamentally important for laboratories, their customers and all parties using and interpreting these results. In conformity assessment, a measurement result is used to decide if an item of interest conforms to a specified requirement. Because of measurement uncertainty, there is always the risk of incorrectly deciding whether or not an item conforms to a specified requirement based on the measured value of a property of the item. Conformity assessment can be quite challenging when the entity measured is so close to the tolerance limits of the specification that its uncertainty, however estimated, critically affects decision-making. In such cases, different decision rules can be used to make statements of conformity. The aim of this paper is to provide a survey of methods for the evaluation of measurement uncertainty in testing, as well as to stress the need for appropriate estimation of measurement uncertainty. This paper also aims to assist testing laboratories in understanding the different decision rules used in conformity assessment and level of risk (such as false accept and false reject) associated with the decision rule employed.

The Evaluation of Expanded Uncertainty of DC Voltages in the Presence of Electromagnetic Interferences using the LabVIEW Environment

The paper presents a possible application of integrated LabVIEW environment to the final evaluation of measurement results in direct measurement. The possibilities of presenting and visualizing the uncertainty of measurement results in a convenient and user-friendly form are also discussed. The topics discussed in the paper were presented using a developed application in LabVIEW. The paper discusses the topic of measurement of direct voltages in the presence of strong electromagnetic interferences. These problems are frequently omitted or hardly emphasized. It presents a suitable measuring system, a virtual measuring instrument created in the LabVIEW environment, and the results of tests carried out for an example NI PCI-6221 data acquisition board. The described approach can be applied also in other measurement situations.

Influence of the Applied Measurement Methodology on the Results of Geometric Measurements of the SB4 Spring Clips

The article presents the results of measurements of the “b” dimension of the SB4 spring clips carried out using three measurement methods that differ in the method and width of the base plate contact. The results obtained are presented and the uncertainty of measurement for each method is estimated. Attention was paid to the issues of the obtained dispersion of the value of the “b” dimension. The tolerated dimensions are discussed. The proposed measurement methods can help to identify shape mismatches of spring clips. Keywords: rail fastening, spring clip, dimensional measurements, clamping force