Electric Field Strength Measurements Research Articles

Design and application of a power frequency electric field measuring device for a high‐humidity environment

AbstractThe power frequency electric field is the most important electromagnetic environmental factor in alternating current power transmission projects. The humidity has a negative influence on available electric field measuring devices, which may lead to discrepancies of up to seven times the actual value at a relative humidity exceeding 80%. The changes in the support and probe shell impedance may be the reason for the error. The optimization measures include modifying the communication mode, designing a suitable structure and circuit for the probe, and using composite insulating material with strong hydrophobicity for the support. A three‐axis omnidirectional electric field measuring device was developed based on wireless communication and composite support. The variation of the measured electric field strength value is less than 1% at relative humidities ranging from 45% to 90% in the laboratory, and the measured results obtained in high humidity at the high‐voltage test site and under the transmission line demonstrated high accuracy. The research demonstrates that the composite support can be used to improve the performance of conventional devices. The proposed device can better meet the needs for accurate measurement of electric field strength in a high‐humidity environment and overcome the technical problems raised by the IEC standard.

Time-resolved investigations of a glow mode impulse dielectric barrier discharge in pure ammonia gas by means of E-FISH diagnostic

Time-resolved electric field strength measurements have been performed, using an electric-field induced second harmonic (E-FISH) diagnostic, in a nanosecond glow discharge of an impulse dielectric barrier discharge, in an ammonia gas environment. A temporal resolution of 2 ns and a spatial resolution estimated at 70 µm (given by laser waist) have been achieved. The comparative study of E-FISH measurements with and without a plasma discharge, operated at 4 kHz, reveal the presence of a persistent counter electric field, which is assumed to be caused by charge accumulation in between the AlN dielectrics used. Furthermore, by studying the influence of the applied voltage, the pressure, and the inter-dielectric distance, measurements seem to indicate the presence of charges remaining also in the post-discharge volume from the previous discharge to the next one.

Разработка нового метода измерения напряженности электрического поля на основе сдвоенного электроиндукционного датчика

A new method for measuring electric field strength is proposed. The method is based on the mean value measurement method, which uses a dual electroinduction spherical sensor. The use of the dual sensor for the method implementation allows to extend the functionality of the method by mean value. The method of measurement by the mean value assumes simultaneous measurement of two values of intensity E1 and E2 in one point of electric field with opposite sign errors. As the theory of construction of the new method has shown, it is possible to determine not only the measurement result as an average of two values of the strengths, but also to estimate the error of the measurement result and tentatively determine the distance to the field source. In order to determine the distance to the field source, a coefficient of the ratio of the two found strengths at each point of the field is introduced, by which the empirical dependence of the relative distance to the field source is found. The relative distance is the ratio between the radius of the spherical sensor and the distance to the field source. By determining the relative distance at each measuring point according to this relationship and substituting it into the known expression for the error, the error of the result at the measuring point is determined. The relative distance is also used to determine the distance to the field source. Thus, the new method of measurement allows to increase the accuracy of measurement of electric field strength, determined by the relative distance to the source of the field.

Prerequisites for Construction of a Device for Measurements of Electric Field Strength with Determination of the Measurement Error

Prerequisites for Construction of a Device for Measurements of Electric Field Strength with Determination of the Measurement Error

Experimental Validation of Enhanced GPR Signals by A Broadband Metasurface

In this paper, the potential of a broadband metasurface for ground penetrating radar (GPR) signal enhancement is investigated by simulation and experiments. Simulation results show that the reflection at the air-MUT interface can be reduced from 35% to 5% over a broad frequency range (relative bandwidth up to 44%) when the broadband metasurface is in place. Measured reflectance is consistent with the simulation results. Meanwhile, the electric field strength measurement results demonstrate that the transmitted electromagnetic signals can be amplified when the reflection is reduced over the same frequency range. GPR experiments verified that clear hyperbolic signals emerged for commonly undetectable pipes when the high-frequency signals are enhanced. The proposed broadband metasurface can be an effective solution for the detection of nonmetallic inclusions in high-lossy media.

Analytical Comparison of Path Loss Models for Radio Wave Propagation over Yenagoa–Southern Nigeria

Using propagation models helps with communication system planning and maximizes the use of the radio spectrum, a limited natural resource. Here is a comparative analysis between some propagation models and actual measurements from Yenagoa, Southern Nigeria. Electric field strength measurements made during drive tests for two television transmitters operating at 210.25 MHz and 577.10 MHz make up the experimental data. Analytical comparisons were made between verified predictions for the free space, Okumura, and Hata models and measured data. The results demonstrate that these empirical models fail to take into account Yenagoa's actual terrain profile for television broadcast. The Okumura model is the best fit, with ideal values for root mean square error (RMSE) of 34.9136 and 33.2841 and average relative error of 0.13212 and 0.4327 for 210.25 MHz and 577.10 MHz, respectively. However, if the Okumura model is tailored for Yenagoa to improve electric field strength prediction and coverage estimation, better results can be attained.

Atom-based sensing technique of microwave electric and magnetic fields via a single rubidium vapor cell.

We present an atom-based approach for determining microwave electric and magnetic fields by using a single rubidium vapor cell in a microwave waveguide. For a 87Rb cascade three-level system employed in our experiment, a weak probe laser driving the lower transition, 5S1/2→5P3/2, is first used to measure the microwave magnetic field based on the atomic Rabi resonance. When a counter-propagating strong coupling laser is subsequently turned on to drive the Rydberg transition, 5P3/2→67D5/2, the same probe laser is then used as a Rydberg electromagnetically induced transparency (EIT) probe to measure the microwave electric field by investigating the resonant microwave dressed Autler-Townes splitting (ATS). By tuning the hyperfine transition frequency of the ground state using an experimentally feasible static magnetic field, we first achieved a measurement of the microwave electric and magnetic field strength at the same microwave frequency of 6.916 GHz. Based on the ideal relationship between the electric and magnetic field components, we obtained the equivalent microwave magnetic fields by fitting the inversion to the measured microwave electric fields, which demonstrated that the results were in agreement with the experimental measurement of the microwave magnetic fields in the same microwave power range. This study provides new experimental evidence for quantum-based microwave measurements of electric and magnetic fields by a single sensor in the same system.

Основы построения струйно-капельных оптических систем трехкоординатных измерений напряженностей электрического, магнитного и гравитационного полей методом висящей капли. Часть 1

The article discusses the principle of operation and the main components of jet-drop optical measuring systems (JDOMS) based on the pendant drop method for monitoring electric field strength (EFS), magnetic field (MFS) and gravitational field (GFS). To make a pendant drop sensitive to electric or magnetic fields, it is proposed to charge it electrostatically or to create it from a magnetic fluid, and its mass allows you to feel changes in the gravitational field. The use of magnetic fluids as the basis of a pendant drop is the most multifunctional for measurements of EFS, MFS and GFS. The implementation of the zero measurement method using a pendant drop as a comparison device, a null organ that perceives the difference in the effects of the measured and reference field(s) at the level of quasi-zero three-coordinate displacements, is considered. They are measured by high-precision optical measurement methods. Different variants of modern optical measurement systems are analyzed.

Observation of strong terahertz field-induced second harmonic generation in plasma filaments.

We report the observation of terahertz field-induced second harmonic (TFISH) generation produced by directly mixing an optical probe beam onto femtosecond plasma filaments. The produced TFISH signal is spatially separated from the laser-induced supercontinuum by impinging on the plasma at a noncollinear angle. The conversion efficiency of the fundamental probe beam to its second harmonic (SH) beam is greater than 0.02%, which represents a record in optical probe to TFISH conversion efficiency that is nearly five orders of magnitude larger than previous experiments. We also present the terahertz (THz) spectral buildup of the source along the plasma filament and retrieve coherent terahertz signal measurements. This method of analysis has the potential to provide local electric field strength measurements inside of the filament.

HF Noise Characteristics over Cyprus

Due to the long distance propagation characteristics of the HF spectrum, noise and interference are significant and challenging factors that have to be addressed in the context of HF system performance. Both aspects exhibit systematic diurnal, seasonal, and solar cycle variability that result in a number of corresponding measurement campaigns all over the globe, in an effort to characterise HF noise. Noise at HF consists of man-made and naturally occurring HF noise with atmospheric and galactic components. An understanding of HF noise variation in terms of time, azimuth, and filter bandwidth is crucial for a specific location, as it can provide a background knowledge based on which appropriate values of HF system parameters may be selected. This paper deals with the temporal, azimuthal, and bandwidth characteristics of HF noise based on a one-month dataset of electric field strength measurements recorded by a directional antenna in Cyprus.

Evaluation of Electromagnetic Field Levels and Student Exposure at Aydın Adnan Menderes University Central Campus

With the effect of developing technology, humanity is constantly exposed to more electromagnetic fields. Regional studies are gaining importance for determining the possible problems. In this study, extremely low-frequency electromagnetic field (ELF-EMF) measurements were carried out in Aydın Adnan Menderes University Central Campus in areas where university students are frequently found, at 25 randomly selected points, in the region where high voltage lines pass and around transformers, and to evaluate the awareness of university students about the ELF-EMF they are exposed to. For this purpose, the necessary magnetic field and electric field strength measurements were made and a questionnaire was applied to determine the awareness level of the students. Results were evaluated by comparing them with the ICNIRP limit values. Accordingly, it has been concluded that Aydın Adnan Menderes University Central Campus can be accepted as a relatively safe area since electromagnetic field exposure values are within the ICNIRP safe limit values. In addition, as a result of the questionnaire, it was determined that the young people were conscious to a certain extent about ELF-EMF, but they did not pay attention to protect themselves against the possible effects of ELF-EMF. It is important to make the necessary initiatives in order to raise awareness of young people on this issue.

Pilot study of a new methodology to study the development of the blue bottle fly (Calliphora vomitoria) under exposure to radio-frequency electromagnetic fields at 5.4 GHz

Purpose Exposure of insects to radio-frequency electromagnetic fields (RF-EMFs) can have developmental effects. However, there is currently no clear understanding of the exposure level that can lead to such effects. Therefore, the goal of this study was to, for the first time, study the development of the Blue Bottle Fly (Calliphora vomitoria, CV) under exposure to RF-EMFs at 5.4 GHz, using both numerical RF-EMF dosimetry with anatomically accurate 3 D models of insects and an RF-EMF exposure experiment. Materials and Methods CV was chosen as a model organism in this study because CV’s development can be influenced thermally and CV’s pupal stage presents a window of several days in which immobile pupae can be exposed to RF-EMFs. The 5.4 GHz frequency was used because it allowed us the license-free operation of the exposure setup. Numerical, EM simulations with 3 D anatomically accurate models of CV, obtained using micro-CT scanning, were used in this study. These simulations enable the estimation of the absorbed power and the whole-body averaged specific absorption rate in CV during RF exposure experiments. An experiment with three exposure conditions was designed and executed in which 400 pupae were split into an exposed group that was placed inside the TEM cell for 48 h and concurrent control. Two exposure conditions used RF-EMF input power into the TEM cell at 5.4 GHz on two different levels. One exposure condition was sham exposure. Electric field strength measurements were used to validate the proper functioning of the exposure setups and to quantify the RF-EMF exposure of the control groups. Results and conclusions All studied groups of pupae – exposed to RF-EMFs, sham, and control groups- showed similar (evolutions of) masses, lengths and diameters during their development. The total rate of pupal emergence was reduced in one of the studied RF-EMF exposures in comparison to its concurrent control, while the other RF-EMF exposure and the sham exposure did not alter the total rate of pupal emergence. The sham exposure and the lowest of the two studied RF-EMF exposure conditions (19.4 V/m) caused a median delay in pupal emergence of 4 and 8 hours, respectively, in comparison to concurrent control groups. The higher studied exposure of 55 V/m caused a median relative acceleration in the development of 8 h.

Measurement of Electric and Magnetic Field Strengths under 765 kV UHVAC Single Circuit Transmission Line

Transmission line corridors of developing countries are increasingly dense and expensive with construction of new ultrahigh voltage (UHV) transmission lines. Right of way of transmission line in the corridor, construction cost of transmission lines including towers, is directly influenced by electric and magnetic field strength emission (EMF) of that line. In UHV range, emission of electric and magnetic field strength in the vicinity of lines is of great public concern, as are likely to have hazardous effects to human being when their exposure level exceeds specified limits. Higher the transmission voltage and stronger the electric field. Though the results on effect of EMF on human being is inconclusive, to create awareness to common public and working professional, it is mandatory to measure the emission level of EMF in lateral and longitudinal profile. This paper reports experiences of EMF emission measurement of 765 kV UHVAC quadruple ACSR bundled conductor single circuit transmission line in India. Measurement results of EMF with vegetation is reported.

The best sensitive single-coordinate interference jet-drop measurement of electric field strength

The article discusses the features of the implementation of highly sensitive single-coordinate measurements of electric field strength (EFS) by using of jet-drop optical measuring systems (JDOMS). The use of moving monodisperse charged droplets of a jet-drop coherent flow, which acquire a displacement depending on the directions of movement, the level of the EFS and of the droplet charge, is discussed. The issues of implementation of stroboscopic interference measurements of droplet displacements under impulsed illumination of their surfaces, used as curved reflectors, are considered in JDOMS. It is shown that measuring the displacements of the reflected oh drop of the laser beam makes it possible to determine the displacements of the reflecting drop and the value of the EFS at the selected coordinate, respectively. The features of the use of liquids with pigments and additives in the form of nanopowders of highly reflective metals, liquid metals (or their alloys) with a low melting point are considered in the JDOMS.

Izloženost učenika srednje elektrotehničke škole "Nikola Tesla" bežičnom elektromagnetnom zračenju

Introduction/Aim: Wireless electromagnetic radiation from routers is an everyday occurrence in the life and work of modern man. They are widely used in many professional, public and domestic facilities, which means that people of all ages can be constantly exposed to electromagnetic radiation from these devices. The aim of this study was to determine the electric field strength, the magnetic field strength, and the electromagnetic exposure of students in different laboratories of the Secondary School "Nikola Tesla", depending on the type of routers installed in them, as well as to check some of the obtained results with the help of the appropriate software program of high-frequency (High-Frequency Simulation Software - HFFSS) for the simulation of electromagnetic radiation through different environments. Methods: Measurements of electric and magnetic field strength, as well as electromagnetic exposure, were carried out using the measuring instrument Spectran HF 60105, on four different types of routers installed in four laboratories of the Secondary School of Electrical Engineering "Nikola Tesla" in Niš. Measurements were realized on each router, through five horizontal and five vertical positions, with a distance of 45o in relation to the horizontal and normal axis of the router, and with spaces of 1 cm, which gives a total number of one thousand measurements. Results: The measured results obtained on four different routers that operated at a frequency of 2.4 GHz for the electric field strength (measured in millivolts per meter), magnetic field strength (measured in microampere per meter) and electromagnetic exposure (in microWatts per square centimeter) were below the limit values defined by standards. The achieved results were verified only for the router TL-WR841HP with the help of HFSS for the simulation of electromagnetic radiation through different environments. The result of the simulation check practically confirms the reliability of the measured results for TL-WR841HP router. Conclusion: Measuring and monitoring electromagnetic radiation is a very important task aimed at preserving and improving the quality of the working and living environment, as well as the quality of life and health of people and children. Software programs for the simulation of electromagnetic radiation can be used when it is not possible to carry out experimental measurements due to technical problems, hindered access to the device, danger of excessive radiation or some other reasons.

Theoretical study of the measurement of electric field strength based on the pendular spectra of linear (HCCCN)n (n = 1−3) molecules

The pendular spectra of linear ( H C C C N ) n ( n = 1 − 3 ) molecules at several rotational temperatures under a certain range of electric field strength E are calculated using the finite element matrix diagonalization method. In addition, the normalized “ Q -branch” intensity ( I Q ) and the gradient ( K E ) of I Q under corresponding conditions are investigated. Based on the results, the range and sensitivity of measuring the electric field strength with linear ( H C C C N ) n ( n = 1 − 3 ) molecules are analyzed. A scheme to measure electric field strength based on ( H C C C N ) n ( n = 1 − 3 ) with high sensitivity is proposed and the spatial resolution is also discussed. The feasibility of measuring the electric field strength of the electrostatic Stark decelerator based on a pendular spectrum is studied.

Detection of features in the series of electric field strength measurements using data transformation and machine learning

Data transformation is a common information processing procedure that can detect features hidden in the data that are not visible in their original form. The article shows some examples of such processing to detect features in the data of long-term observations of the intensity of the surface atmospheric electric field. This uses the data of the EFM 550 field sensor installed in the city of Nalchik. The results are visualized using the Matplotlib Python library to visualize the results of such data processing. The selected data transformation methods are also well suited for machine learning. To demonstrate the possibilities of finding features, several methods of teaching without a teacher are used. It is noted that most of the identified features in the series of measurements of the surface atmospheric electric field are associated with local meteorological phenomena.

ON THE ACOUSTO-MAGNETIC METHOD OF MEASURING THE ACOUSTIC RESISTANCE OF LOCAL AREAS OF THE BIOLOGICAL TISSUE

The subject of study in the article is the acoustic resistance of local areas of the biological tissues in vivo, depending on their pathology. The aim of the work is to develop a quantitative method for measuring the acoustic resistance of local areas of the biological tissue (substance) located inside the human body. The following tasks are solved in the article: development of scientific foundations of the acousto-magnetic method for measuring the acoustic resistance of local areas of the biological tissue; development of a remote method for measuring electrical voltage on the surface of the patient's skin, caused by acousto-magnetic impact on local areas of the tissue and determined by the value of acoustic resistance; calculation of the ratios binding the value of the acoustic resistance of the local areas of the tissue with the electric voltage on the measuring probes on the patient's skin, the values of the acoustic radiation power and the external constant magnetic field, as well as with the distance between the probes and the local area of the biological tissue; verification of the calculated ratios using the experimental determination of the acoustic resistance of the local area of the model biological tissue. The following methods were used: physical modeling of the biological tissue, physical and mathematical modeling of electrical properties of the local part of the biological tissue, calculation of electromagnetic and acoustic parameters of the tissue, experimental measurement of electric field strength excited in the local part of the biological tissue, verification of calculated relations by comparing them with experimental results. The following results were obtained: the scientific foundations of the acousto-magnetic method for the quantitative measurement of the acoustic resistance of local areas of the biological tissue were developed; a remote method for measuring the electric voltage on the surface of the patient's skin caused by the acousto-magnetic effect on local areas of the tissue and the determined value of the acoustic impedance was developed; relations were calculated connecting the value of the acoustic impedance of local areas of the tissue with the electric voltage on the measuring probes on the patient's skin, the values of the acoustic radiation power and external constant magnetic field, as well as the distance between the probes and the local area of the biological tissue; verification of the calculated ratios was carried out using the experimental determination of the acoustic resistance of the local area of the model biological tissue. Conclusions: The scientific foundations of the remote acousto-magnetic method of high-precision measurement of the acoustic resistance of local areas of human biological tissue, confirmed experimentally on model tissue samples, have been developed. The method can make it possible to reveal with high accuracy the functional relations of the measured local value of acoustic resistance with pathological changes in the tissue. At the same time, the influence of the human factor on the interpretation of the recorded values of acoustic resistance (which is characteristic of the traditional, mainly qualitative, rather than quantitative ultrasound method) is excluded, the information content and reliability of acoustic diagnostics are increased.

Analysis of Effect Electric Field Strenght on Safe Distance Below Main Substation Busbar 150 kV

This research is to analyze the effect of electric field strength on the safe distance under the 150kV substation busbar. The research was conducted at 150 kV substation Rancaekek, substation Rancakasumba, substation Cikasungka. The electric field exposure threshold value according to SNI, ICNIRP, IRPA/INIRP and WHO is 10kV / m for the working community. The lowest distance of the busbar conductor to the ground surface is 7.5m. Measurements and calculations of transverse electric field strength from busbar 1 to busbar 2. The height of the test point is 0 m to 2.3 m from the ground surface. From the results of the calculation of the electric field, strength obtained that the shortest minimum safe distance is 7.48 m, while the highest minimum safe distance is 7.88 m. From the results of the measurements of the electric field From the results of measurements of electric field strength obtained that the fastest duration of electric field exposure was 4.42 hours while the longest electric field exposure duration was 5.75 hours. From the calculation of the electric field, strength obtained that: the fastest duration of electric field exposure is 7.56 hours while the longest duration of electric field exposure is 7.91 hours.

Основы построения струйно-капельных оптических систем измерений напряженности электрического поля. Часть 1

The article discusses the principles and possibilities of using jet-drop optical measuring systems for monitoring the electric field strength (EFS). Two applied techniques are considered. First, the deflection of flying charged droplets (balls, hollow granules) used as micro-objects sensitive to EFS and deviating from a given rectilinear trajectory of motion, like an electron in a kinescope. Secondly, stroboscopic determination of the position and/or displacement of drops by pulsed illumination of the side of the deflected drop by the optical flow and measurement of the reflection angle for it. The possibilities of implementing the differential method of EFS measurements are discussed. The features of the use of liquids with the addition of metal nanopowders or based on liquid metals, as well as hollow droplets in the form of microspheres or hollow granules are considered