The combined method for uncertainty evaluation in electromagnetic radiation measurement

Electromagnetic radiation of all frequencies represents one of the most common and fastest growing environmental influence. All populations are now exposed to varying degrees of electromagnetic radiation and the levels will continue to increase as technology advances. An electronic or electrical product should not generate electromagnetic radiation which may impact the environment. In addition, electromagnetic radiation measurement results need to be accompanied by quantitative statements about their accuracy. This is particularly important when decisions about product specifications are taken. This paper presents an uncertainty budget for disturbance power measurements of the equipment as part of electromagnetic radiation. We propose a model which uses a mixed distribution for uncertainty evaluation. The evaluation of the probability density function for the measurand has been done using the Monte Carlo method and a modified least-squares method (combined method). For illustration, this paper presents mixed distributions of two normal distributions, normal and rectangular, respectively

The combined method for uncertainty evaluation in electromagnetic radiation measurement

Electromagnetic radiation of all frequencies represents one of the most common and fastest growing environmental influence. All populations are now exposed to varying degrees of electromagnetic radiation and the levels will continue to increase as technology advances. An electronic or electrical product should not generate electromagnetic radiation which may impact the environment. In addition, electromagnetic radiation measurement results need to be accompanied by quantitative statements about their accuracy. This is particularly important when decisions about product specifications are taken. This paper presents an uncertainty budget for disturbance power measurements of the equipment as part of electromagnetic radiation. We propose a model which uses a mixed distribution for uncertainty evaluation. The evaluation of the probability density function for the measurand has been done using the Monte Carlo method and a modified least-squares method (combined method). For illustration, this paper presents mixed distributions of two normal distributions, normal and rectangular, respectively

Measurement Uncertainty Expression of Capacitive Dividers with Concentrated Parameters in High Frequency Range

Ova disertacija sadrži analizu mogućnosti merenja brzih impulsnih napona i izražavanja odgovarajuće merne nesigurnosti. Dokazano je da je moguće izvršiti numeričku simulaciju odziva mernog sistema na impuls brzine porasta reda veličine pikosekunde. Izražena je merna nesigurnost kapacitivnog razdelnika napona Monte Karlo metodom. Prikazan je način konstruisanja kapacitivnog razdelnika napona sa talasovodnim prilagodnim otporom. Konstruisano je više tipova kapacitivnih razdelnika napona izuzetno dobrih karakteristika. Na osnovu dobijenih rezultata je odabran kapacitivni razdelnik napona najboljih karakteristika i izražena je njegova merna nesigurnostThis thesis contains an analysis of the possibilities for measurement of very fast pulse voltages and proper expression of measurement uncertainty. It has been proven that it is possible to perform numerical simulation to the response of the very fast pulse voltage with rise time at the order of picoseconds of the measuring system. Measurement uncertainty of capacitive voltage dividers is expressed by Monte Carlo method. The way of constructing capacitive voltage dividers with a waveguide resistance is shown in this thesis. The design of four types of capacitive voltage dividers with extremely good features are shown. Based on these results, capacitive voltage divider with best characteristics is selected and its measurement uncertainty is expressed

Measurement Uncertainty Expression of Capacitive Dividers with Concentrated Parameters in High Frequency Range

Ova disertacija sadrži analizu mogućnosti merenja brzih impulsnih napona i izražavanja odgovarajuće merne nesigurnosti. Dokazano je da je moguće izvršiti numeričku simulaciju odziva mernog sistema na impuls brzine porasta reda veličine pikosekunde. Izražena je merna nesigurnost kapacitivnog razdelnika napona Monte Karlo metodom. Prikazan je način konstruisanja kapacitivnog razdelnika napona sa talasovodnim prilagodnim otporom. Konstruisano je više tipova kapacitivnih razdelnika napona izuzetno dobrih karakteristika. Na osnovu dobijenih rezultata je odabran kapacitivni razdelnik napona najboljih karakteristika i izražena je njegova merna nesigurnostThis thesis contains an analysis of the possibilities for measurement of very fast pulse voltages and proper expression of measurement uncertainty. It has been proven that it is possible to perform numerical simulation to the response of the very fast pulse voltage with rise time at the order of picoseconds of the measuring system. Measurement uncertainty of capacitive voltage dividers is expressed by Monte Carlo method. The way of constructing capacitive voltage dividers with a waveguide resistance is shown in this thesis. The design of four types of capacitive voltage dividers with extremely good features are shown. Based on these results, capacitive voltage divider with best characteristics is selected and its measurement uncertainty is expressed

Algorithm for calculating influence of power transformer oil temperature change on the accuracy of allacoustic non-iterative partial discharge localization

Ovaj rad razmatra čisto akustičku metodu za lokalizaciju parcijalnog pražnjenja u energetskom transformatoru. Ova metoda se zasniva na matematičkom modelu koji koristi multilateraciju, princip vremenske razlike kašnjenja signala i neiterativni matematički algoritam. U ovom modelu pretpostavlja se da akustički signal prolazi jedino kroz transformatorsko ulje i da je brzina akustičkog signala konstantna. Brzina akustičkog signala u velikoj meri zavisi od temperature transformatorskog ulja što znači da se i temperatura transformatorskog ulja smatra konstantnom. U realnim uslovima, sa aspekta fizike, termodinamike fluida, konstrukcije transformatora itd., ova pretpostavka je najblaže rečeno velika. Upravo zato se u ovom radu istražuje uticaj promene temperature transformatorskog ulja (promene brzine akustičkog signala) na preciznost razmatrane metode. Za tu namenu, dizajniran je algoritam i implementiran u programskom jeziku Visual C#. Na osnovu sprovedenih simulacija stečena su nova saznanja o interakciji između temperature transformatorskog ulja i položaja akustičkih senzora. Ova interakcija dovela je do značajne razlike u preciznosti neiterativnog matematičkog algoritma za različite položaje akustičkih senzora pri promeni temperature transformatorskog ulja. Kako bi se uočena interakcija maksimalno iskoristila za unapređenje preciznosti razmatrane metode, predloženi su određeni koraci za dalje istraživanje i razvoj.This article investigates the all-acoustic method for partial discharge localization in a power transformer. This method is based on mathematical model that uses multilateration with Time Difference of Arrival (TDOA) principle and non-itterative mathematical algorithm. In this model, it is assumed that acoustic signal propagates only through transformer oil and that the velocity of acoustic signal is constant. Acoustic signal velocity is largely dependent on transformer oil temperature meaning that oil temperature is also considered to be constant. In reality if we look from the perspective of physics, thermo dynamics of fluids, transformer construction etc. this approximation is enormous. Therefore, influence of power transformer oil temperature change (velocity of acoustic signal change) on the accuracy of this method is investigated. For that purpose special algorithm is designed and implemented in Visual C# programming language. Based on conducted simulations, further knowledge is gained about interaction between transformer oil temperature and placement of acoustic sensors. This interaction produced significant disparity in noniterative algorithm's accuracy for different sensor positions with oil temperature change. In order to fully take advantage of noticed interaction, certain steps for further research and development are proposed

Probabilistic analysis of voltage divider ratios

Tolerancija modernih otpornika obično varira od 0.1% do 1 %. Sa probabilističke tačke gledišta to znači da se odgovarajući otpor može posmatrati kao slučajna promenljiva sa odgovarajućom funkcijom gustine raspodele verovatnoće (PDF). Dobijen je izraz za PDF za odnos prenosa dvo-otporničkog razdelničkog napona, kada je otporima u razdelniku dodeljena uniformna raspodela. Grafikoni dobijeni analitičkim izrazima, za različite kombinacije nominalnih otpora i tolerancije dvaju otpornika, upoređeni su sa onima dobijenim numeričkim simulacijama. Asimetrični karakter dobijenog rezultantnog PDF-a, uzrokovan nelinearnošću funkcije razdelničkog kola, implicira da se nominalna, srednja i najverovatnija vrednost razdelničkog odnosa mogu razlikovati. Za normalnu raspodelu otpora u dvootporničkom razdelniku, analitički pristup postaje složen, dok Monte Karlo simulacije lako daju grafikone naponskih odnosa PDF-a i izračunavaju vrednosti njihovih parametara.Tolerance of modern resistors typically ranges from 0.1% to 1%. From the probabilistic viewpoint, this is taken to mean that the corresponding resistance can be treated as a random variable, with an appropriate probability density function (PDF). We derive an expression for the PDF of a two-resistor voltage divider's transfer ratio, when the resistances in the divider are assigned uniform distributions. Plots of the obtained analytical expression, for various combinations of nominal resistances and tolerances of the two resistors, are compared to those produced by numerical (Monte Carlo) simulations. The asymmetrical character of the obtained resultant PDF, caused by non-linearity of the divider's circuit function, implies that the nominal, the mean and the most probable value of the divider's ratio can all differ. For normally distributed resistances in the two-resistor divider, analytical approach becomes complex, while Monte Carlo simulations readily provide the plots of voltage ratio PDFs and calculate the values of their parameters

Probabilistic analysis of voltage divider ratios

Tolerancija modernih otpornika obično varira od 0.1% do 1 %. Sa probabilističke tačke gledišta to znači da se odgovarajući otpor može posmatrati kao slučajna promenljiva sa odgovarajućom funkcijom gustine raspodele verovatnoće (PDF). Dobijen je izraz za PDF za odnos prenosa dvo-otporničkog razdelničkog napona, kada je otporima u razdelniku dodeljena uniformna raspodela. Grafikoni dobijeni analitičkim izrazima, za različite kombinacije nominalnih otpora i tolerancije dvaju otpornika, upoređeni su sa onima dobijenim numeričkim simulacijama. Asimetrični karakter dobijenog rezultantnog PDF-a, uzrokovan nelinearnošću funkcije razdelničkog kola, implicira da se nominalna, srednja i najverovatnija vrednost razdelničkog odnosa mogu razlikovati. Za normalnu raspodelu otpora u dvootporničkom razdelniku, analitički pristup postaje složen, dok Monte Karlo simulacije lako daju grafikone naponskih odnosa PDF-a i izračunavaju vrednosti njihovih parametara.Tolerance of modern resistors typically ranges from 0.1% to 1%. From the probabilistic viewpoint, this is taken to mean that the corresponding resistance can be treated as a random variable, with an appropriate probability density function (PDF). We derive an expression for the PDF of a two-resistor voltage divider's transfer ratio, when the resistances in the divider are assigned uniform distributions. Plots of the obtained analytical expression, for various combinations of nominal resistances and tolerances of the two resistors, are compared to those produced by numerical (Monte Carlo) simulations. The asymmetrical character of the obtained resultant PDF, caused by non-linearity of the divider's circuit function, implies that the nominal, the mean and the most probable value of the divider's ratio can all differ. For normally distributed resistances in the two-resistor divider, analytical approach becomes complex, while Monte Carlo simulations readily provide the plots of voltage ratio PDFs and calculate the values of their parameters

Influence of electromagnetic pollution of the electron beam generator and high-energy radioactive source on the memory components

The study con sid ers the im pact of the en vi ron men tal con tam i na tion by the elec tro mag netic ra di a tion of elec tron beam gen er a tor and high-en ergy ra dio ac tive source on the mem ory com - po nents. Electron beam gen er a tor can be used for in jecting parti cle en ergy into the plasma of the fusion sys tem based on a Marx gener a tor, while ra dio ac tive source as a sim u la tor of high-en ergy ion iz ing ra di a tion that can be caused by the neu tron-in duced ac ti va tion of plasma sur round ing struc tures or re leased from deu te rium-tri tium fu sion re ac tion. The ef - fects of gamma ra di a tion of high-en ergy radio ac tive source and elec tric field of the electron beam gen er a tor on EPROM and EEPROM semi con ductor com puter mem ory, were in ves ti - gated. An older mem ory types were de lib er ately cho sen for the rea son that their more ro bust con struc tion will better pro tect them from the ef fects of ioniz ing and non-ion iz ing ra di a tion. The re sults ob tained un der well-con trolled condi tions show a high de gree of non-re sis tance of the semi con duc tor tech nol ogy to the ex pected elec tro mag netic pol lu tion of the elec tron beam gen er a tor and high-en ergy radio ac tive source. This con clu sion raises doubts on the pos - si bil ity of si mul ta neous ap pli ca tion of elec tron beam gen er a tor, con se quently fu sion sys tem and nanotechnologies with the in creas ing need for min ia turiza tion of electronic com po nent

Stabilization of gas-filled surge arrester's characteristics by use of ionizing radiation

U radu se razmatra stabilizacija električnog pražnjenja u gasovima primenom spoljašnjeg jonizujućeg zračenja. Razmatrano je pražnjenje modela gasnog odvodnika prenapona u pasivnom i aktivnom radnom režimu. Korišćen je originalno razvijen model gasnog odvodnika prenapona. Parametri merenja su bili pritisak gasa i međuelektrodno rastojanje. Primenjeno zračenje je bilo: α-zračenje, γ-zračenje, X-zračenje i neutronsko zračenje. Merenja su vršena pod dobro kontrolisanim laboratorijskim uslovima. Kombinovana merna nesigurnost primenjenog postupka procenjena je na manje od 5%. Dobijenim rezultatima je dato teorijsko tumačenje. Osnovni rezultat je da jonizujuće zračenje ne mora nužno da ograničava funkciju gasnih odvodnika prenapona, već da je, pod određenim uslovima, poboljšava.This paper investigates the stabilization of electrical discharges in gases by means of external ionizing radiation. Discharges in a gas-filled surge arrester model were studied in both passive and active regimes of the device. An originally developed model of the gas-filled surge arrester was used. Gas pressure and the interelectrode gap were the variable parameters in our measurements. Applied radiation types included α-particles, γ-rays, X-rays, and neutrons. Measurements were performed under highly controlled laboratory conditions. The combined measurement uncertainty of the applied procedure was estimated as being under the 5% level. The results obtained are followed by a theoretical explanation. The crucial result is the conclusion that ionizing radiation does not necessarily degrade the gas-filled surge arrester's functionality but that it, rather, improves it under certain conditions

The influence of the ageing temperature on different properties of the EN AW-7075 aluminium alloy

The influence of the ageing temperature on the hardness, electrical conductivity, thermal diffusivity and thermal conductivity of the EN AW-7075 aluminium alloy was studied in this paper. After solution treating the alloy at 480 °C for 1 h and quenching it in ice water, the investigated alloy was characterized using Differential Thermal Analysis (DTA) in order to determine the optimal temperatures for the isochronal ageing treatments. Afterwards, isochronal ageing was conducted at the temperature range of 110 °C-250 °C for 30 min The hardness, electrical conductivity, thermal diffusivity, thermal conductivity and microstructural features were investigated during the ageing treatments. Hardness had a peak value after ageing at 150 °C, while other properties gradually increased with the ageing temperature. Microstructural investigation of the aged alloy by SEM-EDS revealed the existence of precipitated phases that appear homogenously distributed in the microstructure