Penetrant testing (PT) is one of the first ever industrial established non-destructive testing for detecting surface discontinuities. Because of its outstanding sensitivity as well as easy use this test procedure is even today widely used in various fields of industry. As example can be mentioned automotive industry or aerospace industry. PT also can be used for manually testing of single parts as well as automatically testing of repetition parts in serial production. Increasing of demands with respect to quality assurance aspects requires procedures to verify the test itself. Developing...
In technical practice there is very often a requirement of axial force determination in important structural elements of a building or engineering structure during its construction or operational state. In civil engineering practice, five experimental techniques are usually used for evaluation of axial tensile forces in these elements. Each of them has its advantages and disadvantages. One of these methods is the magnetoelastic method. The paper presents general principles of the magnetoelastic method, the magnetoelastic sensor layout and actual information and knowledge about practical...
Optical metrology has an increasing impact on observation and experimental activities in Civil Engineering, contributing to the investigation and development of innovative, non-invasive techniques applied in testing and inspection of infrastructures to ensure safety and quality of life. Advances in specific applications are presented in the paper, highlighting the application cases carried out by LNEC (the Portuguese National Laboratory for Civil Engineering). The examples include: (i) structural monitoring of a long-span suspension bridge; (ii) use of close circuit television (CCTV) cameras...
The EMC (Electromagnetic Compatibility) is one of the most important sectors in electronic industrial and in retail area as well. As more devices and “gadgets” are connected to network via wireless communication as more challenging to avoid any malfunctioning during normal operation. The main focus is to determine how much noise come from our devices and how much they can be immune to noises before causing any problem in their normal operation. Because this high sensitivity, reaction and interaction of the environmental factors - building - EMC chamber – measurement equipment and UUT (unit...
This article contains a description of the technical, process-related and organizational procedures which accredited calibration laboratories use as a model for defining internal processes and regulations. By implementing these procedures, it is ensured that the devices to be calibrated are all treated equally in the various calibration laboratories and that the continuity and comparability of the work of the calibration laboratories are improved. The calibration certificates issued by the accredited laboratories prove the traceability to national standard as required by Standard HRN EN...
The accepted way of expressing measurement results is through an estimated value and its associated measurement uncertainty. Part of the uncertainty evaluation is also to consider mutual sources of uncertainties, called covariance. This paper will describe a CMM 3D measurement and its uncertainty evaluation. A 3D measurement considered here is a length measurement in three orthogonal directions along the x, y, z axes of a Cartesian coordinate system. When a point in 3D space is located it is considered to be a direct method of measurement. However, when it comes to geometrical features such...
Lighting has a major role to environmental comfort and energy efficiency in buildings, being related to parameters that establish comfortable visual environment suitable for the execution of visual tasks. The lighting of interior spaces can be accomplished using natural light, artificial light or, preferably, using a combination of the two. The measurement of Daylight Factor (DF) is required as a quantity to characterize the indoor luminous environment in buildings. The measurement of lighting conditions is usually carried out taking into account the recommendations and the reference...
Measurement uncertainty undoubtedly plays a large role in the assessment of compliance with certain specifications. For example, the widely accepted ILAC G8:09/19 publication gives relatively flexible guidelines for assessing the conformity of certain instruments to their respective standards or specifications. On the other hand, the information given in calibration certificates is often interpreted too rigorously which can, unfortunately, lead to the false conclusion that the instrument in question doesn’t actually meet the client’s specified requirements. In the following paper we will...
ISO 19036 is an international standard that specifies and gives guidance for the estimation and expression of measurement uncertainty (MU) associated with quantitative results of microbial counts in foods. Standard describes top-down or global approach to MU, in which MU is calculated from experimental results with replication of the same analyses as part of the measurement process and expressed as a standard deviation of reproducibility of the final result. In a new revision from 2019 standard ISO 19036 considers three types of MU component: technical uncertainty, matrix uncertainty and...
In this paper is analysed the influence of the expanded uncertainty in the conformity assessment based on the international standards and documents. The different approaches for the calculation of combined standard uncertainties are given, based both on the worst possible consideration up to the implementation of corrections as appropriate. Furthermore, the influence of the effective degrees of freedom and t-distribution is pointed as well. The calculations are presented on the example of the testing and/or inspection of the current instrument transformers test for accuracy.