The article deals the vibration of contacts of electro-mechanical relays (and mechanical contacts generally), its properties, its measurement and a special measuring instrument built for this purpose.
The vibration of contacts is caused by ringing of the springs (and other mechanical components) carrying the contacts. It generates quasiperiodic interruptions of current flowing through a moving contact-pair. These interruptions cause problems e.g. when this current controls fast semiconductor circuits or when the contact-pair is loaded by a remarkable current and sparks and burning of contacts comes in. To avoid these problems some linear or nonlinear filters must be introduced. The measurement of this phenomena has shown that the vibrations mentioned here affect remarkably the time parameters (different delays) describing the behavior of the relay and that these parameters become to be random. The statistical characteristics of these parameters contain information about the technical (diagnostic) state of the relay, which is important for estimation of the behavior of the relay in future. Finally, the basic data of the measuring instrument are introduced.

The paper solves a physical quantity measurement enhancement problem under a shifted power sensor-transfer function with known and unknown values of its power exponent n. The problem is solved on the basis of a functionalalgorithmic method, used to linearize a general transfer function, existing for a digital meter, as well as of a redundant measurements method, used for automatic correction of systematic errors. It is shown, that the distinctive feature of the former method is application of respective quantities substitution formulas. The essence of the proposed methods is described. The redundant measurements equations are derived.

This paper presents the use of numerical finite element (FE) technique for modelling and design of capacitive sensors. The general mathematical approach to FE modelling and design of capacitive sensors is established. Two case studies are considered to show the versatility and efficiency of the developed modelling methodologies. The first involves a multielectrode capacitive sensor for two-phase flow imaging and the second – a robust capacitive angular position sensor. It is shown that although these sensors are used in very different applications, the same modelling strategies are applicable to both cases. Results are presented in terms of sensor performance characteristics for various design parameters and operational regimes. Modelling results are compared with experimental data to validate the adopted modelling strategies.

A proposal for a lossless adaptive compression algorithm to be used in continuous measurement data recording is presented in this paper. The operation implemented by the algorithm can be termed the signal compression before quantization. Although the algorithm itself is inertialess, its efficiency depends on the dynamics of the measurement signal compression. Thanks to the adaptation of the compression algorithm parameters to the variability characteristics (i.e. to the dynamics) of the signals recorded, the compression level can be optimised. The algorithm, method for the adaptation of the algorithm parameters and the compression effect obtained for exemplary measurement signals are presented in this paper.

The Hungarian products must satisfy the increasing quality demands being in Hungary and in abroad. Developing the quality of the machine production is essential requirement of competitiveness of the Hungarian industry. The Department of Production Engineering applies a wide range of the Computer Aided Industrial Metrology and Quality Assurance Softwares in education and in research. The paper introduces some methods for solving of the quality assurance tasks.