9762 papers found
During the maintenance of the intrinsically safe electric circuits in the hazardous area connecting, disconnecting of the intrinsically safe apparatus and short circuits are acceptable. In this moment the intrinsically safe measurement line is in a transient state. In the article the results of the research on the transient states in the measurement line in the 4-20mA standard are presented.
The modern development of electric power systems is increasingly demanding for high improvements in the accuracy of metering and testing methods in both HV and high current, namely, in testing the instrument transformers. The necessity of determining if the existing instrument transformers are usable for harmonic measurements is, at present, also required. The illustrated Instrument transformer bridges implement the, at present, used ratio transformer bridge to testing the instrument transformers and their usability for harmonic measurements. The illustrated bridges uses two ratio...
In this paper the configuration of the test measurement channel for examination of the adaptational algorithms is presented. The measurement channel additional units and auto-calibration algorithms enable to designee its actual characteristics in operation condition and finally to perform the correction of measurement result as well as the assessment of its uncertainty. The basic idea of concerned procedure were shown in [1].
In digital sampling electricity meters calibration procedure is used to set the parameters of the device and to correct the errors of measurement. Electronic calibration station EKS 05-3, used to calibrate electricity meters, is described and its function is explained. The developed calibration software for the calibration of the designed and constructed PEM 6711 digital sampling electricity meter is also described.
In this paper is presented a system, developed at IEN, for determination and measure of pressure coefficients of high precision standard resistors used to maintain the unity of dc electrical resistance, and to transfer the traceability during the periodic international key comparisons established to verify the degree of equivalence of standard among different National metrological Institutes results (NMIs). Preliminary results of the utilisation of the system for the characterisation of high precision standard resistors vs. environment pressure are also given.
The equipment described in this paper has been developed on the basis of the requirement for a calibration pressure sensor based on the use of a conductive elastomer. The testing procedure is described. Our calibration system enables the sensor to be loaded by a square constant static mechanical pressure with a regulable value or by a dynamic pressure step function.
In the paper there are presented some important aspects of education of the measurement and controlling different electrical and non-electrical quantities in the hazardous areas. Special attention is put on the diagnostics and calibration matters. It concerns maritime industry, but the problem is similar in the ashore industry and shown considerations can be easily adapted.
Auto balance RLC bridges are the most common instruments for impedance measure-ments on low frequencies. . Both national metrology laboratories (NMLs) and secondary laboratories (SLs) maintain the scale of ac resistance, inductance and capacitance with sets of artifact standards. In NMLs, the traceability chain for the impedance scale involves a set of coaxial ac ratio bridges, the primary standard being the calculable capacitor. The illustrated new ratio transformer bridges may operate using as reference a capacitor standard covering the whole required frequency range. Experimental bridges...
In this paper the actual practice in measurement result accuracy assessment, following ship classification societies regulations, is presented. Some considerations connected with uncertainty theory applicability to the ship instrumentation conditions are shown. The idea of measurement instrumentation adapted to the marine operation specificity is proposed.
In this paper DAC static parameter definitions are evaluated highlighting their differences and similarities. Great attention has been paid to the most commonly used specifications. As a result of this analysis a unique set of DAC specifications is proposed considering that each parameter has to be unambiguously defined and practically measurable.