Testing of safety of electrical appliances is very important for assuring of safety of users. One of the safety tests is testing of heating of appliances and their surrounding. The test is performed in a measurement system so called "black test corner", which is partially standardised. Measurement of heating is performed with thermocouples. This paper describes the analysis of the influence of the measurement uncertainty of a cold junction of a thermocouple in testing of heating. Heating of appliances is measured as a difference between the temperature of the appliance and the temperature of...
Co-ordinate measuring machines (CMMs) are often used for calibrating different kinds of squares. A procedure for calibrating squares on the CMM Zeiss UMC 850 was developed in our laboratory to cover primarily industrial needs. The uncertainty analysis that was performed for this procedure is introduced in the article. The most important uncertainty contributions were evaluated experimentally. Many experiments were also performed in order to find the most appropriate calibration position in the CMMs measurement space. About 2000 measurement points were taken in order to get reliable results...
Centro Español de Metrología (CEM), Spanish Metrological Institute, as part of its activity, has started to prepare primary reference gas mixtures using gravimetrical method. As a consequence of this new work, a comparison of some primary reference gas mixtures prepared by CEM has been carried out with three of the gas mixtures manufacturers established in Spain. CEM has coordinated this comparison with the manufacturers in order to assure traceability in equipments for the automotive exhaust gas field. The objetive of this comparison is double: • to compare the analytical results with the...
In practice, quantization of a measured quantity often significantly influences observation values. A typical example is found in measurements using digital instruments. In some cases, due to the quantization, no dispersion is observed among repeated measurements. The type A evaluation then gives zero standard uncertainty. In such a case, the most common practice is to assume, as an a priori distribution in type B evaluation, a uniform distribution, the width of which is given by the quantization interval, and take the width divided by square root of 12 as the standard uncertainty. This...
This study is mining the error factors in the uncertainty measurement data. The purpose is to be advanced the accuracy control for QC (Quality control) of BCA (Blood Chemical Analysis). BCA is often taken as uncertainty data. On the QC of calibration curve, it is important to securing an intermediate accuracy in the measuring system of ISO-GUM (International Organization for Standardization-Guide to the express of Uncertainty Measurement). In the technology of ISO-GUM, the analysis method of traceability, transferability and compatibility are applied. Already we have reported the uncertainty...
It is possible to compute uncertainty in the form of confidence intervals. In this article is exploited the confidence intervals determination through a simulation study that enables to evaluate uncertainty in the form of confidence intervals for real measurements of inter-laboratory comparison (ILC) even for small numbers of observations. Here are listed estimation approaches (mathematical-statistical algorithms) for the determination of the consensus value (the true measured value); confidence interval for the true measured quantity in different laboratories; determination (estimate) of...
In a world where the gap between the macro and the micro scales is on the increase, measurement and measurement procedures assume significant importance. In an effort to produce high quality products, industries employ state-of-the-art manufacturing techniques. The best manufacturing techniques would be meaningless without being complimented by the best measurement system and procedures in order to get accurate measurement results. The present industrial scenario is such that the measurement process has become increasingly tedious and also subject to a lot of constraints. Traceability (VIM...
The paper is concerned with attempts to investigate the influence of measurement results errors, the algorithms for signal values recovering between the measurement actions, time discrete period, the samples number, and the interval of signal observation as well as other factors on the procedures of statistic treatment of measurements results. The application of the obtained procedures for measurement precision assessment to knowledge base creation provides a possibility to increase the intelligent measurement efficiency.
The evaluation of measurement uncertainty, from the final user’s standpoint, involves several issues which are only partially addressed by the GUM. An evaluation procedure assisted by a computer program can be of great support and provide the user with detailed results useful for further analysis. In this paper a code is presented for the assisted evaluation of measurement uncertainty, based upon the convolution of probability distributions. So the method allows expression of the final result of measurement as a probability distribution, on which it is possible to evaluate useful parameters...
Requirements for validation of custom developed software in metrology applications are mainly influenced by technical realisation of measuring instrument/system. In this article some issues related to the technical realisation of validated software are described. Furthermore, the state-of the art validation approaches and tools are presented, including failure risk analysis and test case selection. In the discussed example the validation approach in case of MIRS Mass Laboratory automation software is presented. Synthesis of presented methods, tools and techniques may be useful as guidance...