Wyniki wyszukiwania - Biblioteka Nauki

1

Levels of electromagnetic fields from rail vehicles in the context of formal requirements

100%

Miszkiewicz A. , Tchórzewski K.

Problemy Kolejnictwa

|

2020

|

tom Z. 187

109--116

EN

The article discusses the issue of electromagnetic field levels emitted from rail vehicles with regard to civil protection. The article presents the lack of legal solutions, limits and research methods in the railway industry in Poland. It also depicts the initial results of measurements from rail vehicles. Based on the findings, taking into consideration the measurement results and suppression of electromagnetic waves in free space, electromagnetic fields may reach substantial levels which can affect people’s health and life. The authors of the article conclude that the problem should not be ignored and requires further research, bearing in mind the progressing saturation of all rail vehicles with devices and electronic systems which will serve as sources of electromagnetic fields.

2

The pattern of the electromagnetic field emitted by mobile phones in motor vehicle driving simulators

100%

Politański P. , Bortkiewicz A. , Zmyślony M.

International Journal of Occupational Medicine and Environmental Health

|

2013

|

tom 26

|

nr 3

471-476

EN

Introduction: The paper reports the results of the determinations of UMTS EMF distributions in the driver's cab of motor vehicle simulators. The results will serve as the basis for future research on the influence of EMF emitted by mobile phones on driver physiology. Materials and Methods: Two motor vehicle driving simulators were monitored, while an EMF source was placed at the driver's head or on the dashboard of the motor vehicle driving simulator. For every applied configuration, the maximal electric field strength was measured, as were the values at 16 points corresponding to chosen locations on a driver's or passenger's body. Results: When the power was set for the maximum (49 mW), a value of 27 V/m was measured in the vicinity of the driver's head when the phone was close to the head. With the same power, when the phone was placed on the dashboard, the measured maximum was 15.2 V/m in the vicinity of the driver's foot. Similar results were obtained for the passenger. Significant perturbations in EMF distribution and an increase in electric field strength values in the motor vehicle driving simulator were also observed in comparison to free space measurements, and the electric field strength was up to 3 times higher inside the simulator. Conclusions: This study can act as the basis of future studies concerning the influence of the EMF emitted by mobile phones on the physiology of the driver. Additionally, the authors postulate that it is advisable to keep mobile phones at a distance from the head, i.e. use, whenever possible, hands-free kits to reduce EMF exposure, both for drivers and passengers.

3

Vlianie vysokocastotnyh elektromagnitnyh polej na process adsorp'cii asfal’tenov

100%

Kovaleva L. A. , Kamaltdinov I. M. , Zamula U. S. , Stepanova Z. U. , Haritonova I. V.

Prace Naukowe Instytutu Nafty i Gazu

|

2012

|

tom nr 182 wyd. konferencyjne

639--644

EN

The experimental results of the polar hydrocarbon adsorption in saturated porous media after radio-frequency (RF) electromagnetic (ЕМ) influence and the thermal heating for comparison are presented. Temperature dependences of the extracted volume of hydrocarbons from models are shown. Comparing the obtained data an additional influence of RF ЕМ field on the desorption of asphaltenes from the porous media surface has been found, that leads to an increase of the extraction of hydrocarbons from the models. The thermodynamic substantiation and mathematical modeling of heat and mass transfer in а saturated porous media under RF ЕМ influence are used as the basis of theoretical study. The equation of sorption kinetics based on the Henry's Law including а summand that represents the contribution of thermal and ЕМ fields is to be considered. Researches have discovered that the adsorption process slows down under RF ЕМ field influence, which has а positive effect on the filtration ability of the saturated rock. Investigation of the field influence on the asphaltene adsorption process using atomic force microscopy (AFM) was conducted to identify the mechanism of adsorption and desorption of polar components on the surface of the porous medium under the RF EM field influence.

4

Subjective complaints of people living near mobile phone base stations in Poland

100%

Bortkiewicz A. , Gadzicka E. , Szyjkowska A. , Politański P. , Mamrot P. , Szymczak W. , Zmyślony M.

International Journal of Occupational Medicine and Environmental Health

|

2012

|

tom 25

|

nr 1

31-40

EN

Objectives: The aim of our study was to assess the health conditions and subjective symptoms of the inhabitants living in the base stations vicinity and to analyse the relationship between the complaints and level of exposure to electromagnetic fields (EMF). Materials and Methods: Our study was performed in housing estates located in five regions of Łódź. The electric field measurements were performed in the buildings located closest to the azimuth of the antennas. Respondents were selected by trained interviewers using an uniform procedure. The number of the households to be examined was set at a minimum of 420. The questionnaire contained: demographic data, occupational and environmental exposure to EMF, health condition, subjective complaints. Results were adjusted for confounders (age, gender, EMF at the workplace and EMF emitted by household equipment) using multiple regression model. Results: 181 men and 319 women from 500 households were examined. Electric field above 0.8 V/m was recorded in 12% of flats. There was no significant correlation between electric field strength and the distance of examined flats from the base stations. To make possible comparison with relevant literature, we analysed also the frequency of the reported symptoms vs. the distance. Headache was declared by 57% people, most frequently (36.4%) living 100–150 m away from the base station compared to people living at longer distances (p = 0.013). 24.4% subjects, mostly living at a distance above 150 m, declared impaired memory. Difference was statistically significant in comparison with people living at other distances (p = 0.004). Conclusions: The explanation why we did not find any correlation between the electric field strength and frequency of subjective symptoms but found a correlation between subjective symptoms and distance from base station needs further studies. Maybe new metrics of exposure assessment should be adopted for this purpose.

5

Elektroniczne systemy sygnalizacji kradzieży jako źródła pól elektromagnetycznych

100%

Marzec S. , Nowicka J.

Zeszyty Naukowe Wyższej Szkoły Zarządzania Ochroną Pracy w Katowicach

|

2008

|

tom Nr 1(4)

57-66

PL

W artykule omówiono elektroniczne systemy sygnalizacji kradzieży jako źródła pól elektromagnetycznych. Scharakteryzowano systemy antykradzieżowe radiowe RF i akustycznomagnetyczne AM jedno- i wieloantenowe oraz przedstawiono własne wyniki pomiarów natężenia pola emitowanego przez dwuantenowe akustycznomagnetyczne bramki typu ULTRA POST II, stosowane w hipermarketach. Wykazano, że w odległości do 10 cm od badanych bramek występuje pole elektromagnetyczne o natężeniu odpowiadającym pośredniej strefie ochronnej. Ponieważ w obszarze tym nie przebywają pracownicy, nie ma potrzeby oznaczać źródeł ani granic stref ochronnych. Natomiast wskazane jest zbadanie natężenia pola elektromagnetycznego innych bramek, zwłaszcza emitujących pole o częstotliwości powyżej 3 MHz, dla których dopuszczalne narażenie ludności i pracowników jest znacznie mniejsze niż na pola o mniejszej częstotliwości.

EN

In this article the electronic anti theft systems as the electromagnetic fields sources were discussed. The RF radio and the mono antennas and multiple antennas AM magnetoacoustic anti theft systems were summarized and also the measurement own results of the field intensity beamed by two-antennas gates ULTRA POST II were presented. It was revealed that 10 cm from the examined gates the electromagnetic field is occurred, with the intensity corresponding the intermediate protective zone. In this area the workers stay away, so the sources or protective zones borders marking isn’t needful. However, the examination of the other gates electromagnetic field intensity is advisable, especially these beamed above 3 MHz frequency electromagnetic fields, from which the acceptable population and workers exposure is greatly slighter.

6

Pola elektromagnetyczne w otoczeniu urządzeń fizykoterapeutycznych - aplikatory do terapii zmiennym polem magnetycznym

100%

Karpowicz J. , Gryz K. , Zradziński P.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

|

2009

|

tom Vol. 15, nr 1

44-48

PL

W artykule scharakteryzowano ekspozycję na zmienne pola magnetyczne wytwarzane przez urządzenia do magnetoterapii oraz ocenę oddziaływania tych pól na otoczenie. Na podstawie badań wykonanych przy ponad 60 aplikatorach do terapii polem magnetycznym ustalono, że pola stref ochronnych ekspozycji zawodowej oraz pola, w których mogą powstać zakłócenia pracy implantów medycznych, występują w odległości do 40-70 cm od środka różnych aplikatorów szpulowych o średnicy od 20 cm do 60 cm. Pola, w których mogą powstać zakłócenia urządzeń elektronicznych, występują w odległości do 200-300 cm od aplikatorów szpulowych. Zasięgi oddziaływania pól wytwarzanych przez innego typu aplikatory są wielokrotnie mniejsze.

EN

The exposure to time-varying magnetic field emitted by devices for magnetic field therapy and evaluation of their influence on the environment, are characterized. Examina-tion of magnetic fields emitted by over 60 applicators shown that magnetic fields of the level exceeding generał public permissible exposure or exposure permissible for users of medical electronic implants can be found in the distance up to 40-70 cm from the centrę of various reel applicators of diameter of 20-60 cm. Magnetic fields, by which electronic devices can be affected by the field are present in a distance up to 200-300 cm from the reel applicators. Other types of applicators emit fields of lower level.

7

Evaluation of exposure to electromagnetic radiofrequency radiation in the indoor workplace accessible to the public by the use of frequency-selective exposimeters

100%

Gryz K. , Karpowicz J. , Leszko W. , Zradziński P.

International Journal of Occupational Medicine and Environmental Health

|

2014

|

tom 27

|

nr 6

1043-1054

EN

Objectives: The aim of the study was to identify and assess electromagnetic radiofrequency radiation (EMRR) exposure in a workplace located in a publicly accessible environment, and represented by offices (where exposure is caused by various transmitters of local fixed indoor and outdoor wireless communication systems). Material and Methods: The investigations were performed in 45 buildings (in urban and rural areas in various regions of Poland), using frequency-selective electric field strength (E-field) exposimeters sensitive to the EMRR with a frequency range of 88–2500 MHz, split into 12 subbands corresponding to the operating frequencies of typical EMRR sources. The variability of the E-field was analyzed for each frequency range and the total level of exposure by statistical parameters of recorded exposimetric profiles: minimum, maximum, median values and 25–75th – percentiles. Results: The main sources of exposure to EMRR are mobile phone base transceiver stations (BTS) and radio-television transmitters (RTV). The frequency composition in a particular office depends on the building’s location. The E-field recorded in buildings in urban and rural areas from the outdoor BTS did not exceed respectively: medians – 0.19 and 0.05 V/m, 75th percentiles – 0.25 and 0.09 V/m. In buildings equipped with the indoor BTS antennas the E-field did not exceed: medians – 1 V/m, 75th percentiles – 1.8 V/m. Whereas in urban and rural areas, the median and 75th percentile values of the E-field recorded in buildings located near the RTV (within 1 km) did not exceed: 1.5 and 3.8 V/m or 0.4 and 0.8 V/m, for radio FM band or for TV bands, respectively. Conclusions: Investigations confirmed the practical applicability of the exposimetric measurements technique for evaluating parameters of worker’s exposure in both frequency- and time-domain. The presented results show EMRR exposure of workers or general public in locations comparable to offices to be well below international limits.

8

Computational electromagnetics for design optimization: the state of the art and conjectures for the future

100%

Sykulski J. K.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2009

|

tom Vol. 57, nr 2

123-131

EN

The paper reviews the state of the" art in modern field simulation techniques available to assist in the design and performance prediction of electromechanical and electromagnetic devices. Commercial software packages, usually exploiting finite element and/or related techniques, provide advanced and reliable tools for every-day use in the design office. At the same time Computational Electromagnetics continues to be a thriving area of research with emerging new techniques and methods, in particular for multi-physics applications and in the area of multi-objective optimization.

9

Lorentz Transformation of Radiation 4-Potential

88%

Comay E.

Acta Physica Polonica A

|

2018

|

tom 133

|

nr 5

1294-1298

EN

The laws of Maxwellian electrodynamics are used in an analysis of the structure of the 4-potential of radiation fields. The paper examines multi-particle and single-particle effects of a radiating source. Causality of electromagnetic processes is an important element of the analysis. Covariance properties of the relevant variables are examined and the apparent non-covariance of the radiation 4-potential where A_{0}≡0 in all frames is explained. It turns out that the origin of this feature stems from the multi-charge properties of radiation. It is also shown how in every Lorentz frame one can use covariant properties of radiation fields and reconstruct an appropriate 4-potential.

10

Modal-frequency spectrum of magnetic flux density in air gap of permanent magnet motor

88%

Witczak P. , Kubiak W. , Lefik M. , Szulakowski J.

Archives of Electrical Engineering

|

2014

|

tom Vol. 63, nr 1

29-46

EN

The classic relationships concerning the harmonic content in the air gap field of three-phase machines are presented in form of series of rotating waves. The same approach is applied to modeling of permanent magnet motors with fractional phase windings. All main reasons of non-sinusoidal shape of flux density distribution, namely, magnets’ shape and their placement, slotting, magnetic saturation and eccentricity are also related to their counterparts in modal-frequency spectrum. The Fourier 2D spectrum of time-stepping finite element solution is confronted with results of measurements, with special attention paid to accuracy of both methods.

11

Biological risk assessment of high-voltage transmission lines on worker’s health of electric society

88%

Bidi M.

Archives of Electrical Engineering

|

2020

|

tom Vol. 69, nr 1

57--68

EN

A probable risk for different diseases has been reported due to exposure of peoples living in the vicinity of electrical substations and electrical workers. The aim of this paper is to examine and reduce the induced current density due to the power system field acting on human beings in the working environment, by using the spheroidal calculation model. The results obtained by means of computer programs developed by the author in the MATLAB environment are compared with the limit values given by the International Committee on Non-Ionizing Radiation Protection (ICNIRP) for demonstrating the degree of danger due to the induced current and have a certain guidance function for worker’s health to ensure their safety

12

Evaluation of potential dangers of Mobile Telecommunication frequencies and modulations

88%

Bamisaye A. J.

Journal of Telecommunications and Information Technology

|

2013

|

tom nr 2

30--34

EN

Mobile Telecommunication is one of the fastest growing technologies in the world. The effects of its high frequencies and complex modulations to the exposed population are considered in this paper. Experimental studies examining a variety of effects on all levels of the organism, ranging from effects on single cells to effects which manifest themselves as reactions of the entire body, there have been a number of epidemiological studies in order to establish the possible causal correlations between higher exposures to HF EMFs. Recommendations on the reduction of the effects of EMFs of Mobile Telecommunication on humans was presented.

13

Plasma thyroid hormones and corticosterone levels in blood of chicken embryos and post hatch chickens exposed during incubation to 1800 MHz electromagnetic field

88%

Pawlak K. , Sechman A. , Nieckarz Z.

International Journal of Occupational Medicine and Environmental Health

|

2014

|

tom 27

|

nr 1

114-122

EN

Introduction: This study attempted to determine the effect of a 1800 MHz electromagnetic field (EMF) (only carrier frequency) on thyroxine (T₄), triiodothyronine (T₃) and corticosterone (CORT) concentrations in the blood plasma of chick embryos, and to investigate the effect of electromagnetic field (EMF) exposure during embryogenesis on the level of these hormones in birds that are ready for slaughter. Material and Methods: Throughout the incubation period, embryos from the experimental group were exposed to a 1800 MHz EMF with power density of 0.1 W/m², 10 times during 24 h for 4 min. Blood samples were collected to determine T₄, T₃ and CORT concentrations on the 12th (E12) and 18th (E18) day of incubation, from newly hatched chicks (D1) and from birds ready for slaughter (D42). Results: The experiment showed that T₄ and T₃ concentrations decreased markedly and CORT levels increased in the embryos and in the newly hatched chicks exposed to EMF during embryogenesis. However, no changes were found in the level of the analyzed hormones in the birds ready for slaughter. Differences in T₄ and T₃ plasma concentrations between the EMF-exposed group and the embryos incubated without additional EMF were the highest in the newly hatched chicks, which may be indicative of the cumulative effect of electromagnetic field on the hypothalamo-pituitary-thyroid axis (HPT). Discussion: The obtained results suggest that additional 1800 MHz radio frequency electromagnetic field inhibits function of HPT axis, however, it stimulates hypothalamo- pituitary-adrenal axis by inducing adrenal steroidogenic cells to synthesize corticosterone. Further investigations are needed to elucidate the mechanisms by which radio EMFs affect HPT and HPA axis function in the chicken embryos.

14

Flexible Scenarios Based System for Scientific Computing

88%

Szmurło R. , Starzyński J. , Chaber B. , Wincenciak S.

Przegląd Elektrotechniczny

|

2012

|

tom R. 88, nr 4a

117-119

PL

Technologia obliczeń w chmurze otwiera nowe perspektywy w zakresie symulacji naukowych. Zaawansowane systemy symulacyjne mogą być z jej pomocą udostępniane w postaci dostępnych na żądanie usług, co zmniejsza koszty i zwiększa możliwość stosowania przez użytkowników końcowych. W artykule przedstawiono implementację systemu udostępniającego narzędzia do numeryczenj symulacji pola elektromagnetycznego lekarzom i inżynierom zajmującym się problematyką bezpieczeństwa i higieny pracy, którzy nie są ekspertami w dziedzinie symulacji komputerowych. Przyjazność systemu dla użytkownika została połączona z elestycznością konfiguracji, skalowalnościa i rozszerzalnością przez zastosowanie konfigurowalnych scenariuszy użycia. Celem autorów jest szczegółowa prezentacja tej koncepcji.

EN

Cloud computation technologies open a new perspective for scientific computing. Sophisticated software can now be made available as on-demand service, reducing costs and broadening accessibility for end-users. The paper presents an implementation of a system serving open source electromagnetic field simulation software as a web based service. The primary users of the system are medical staff and electromagnetic safety engineers which are usually not familiar with field simulation methods. The user friendliness of a system combined with its flexibility, scalability and extendibility is realized with help of carefully designed concept of configurable usage-scenarios. Our aim is to present this scenarios concept in detail.

15

The risk of subjective symptoms in mobile phone users in Poland – An epidemiological study

88%

Szyjkowska A. , Gadzicka E. , Szymczak W. , Bortkiewicz A.

International Journal of Occupational Medicine and Environmental Health

|

2014

|

tom 27

|

nr 2

293-303

EN

Objectives: To assess the type and incidence of subjective symptoms related to the use of mobile phones in Polish users. Material and Methods: The study was conducted in 2005 using a questionnaire survey. Although it has been quite a long time, up to now, no such data have been published for Poland. The questionnaire consisted of 53 questions concerning sex, age, education, general health, characteristics of a mobile phone (hand-held, loud-speaking unit) as well as the habits associated with its use (frequency and duration of calls, text messages, etc.) and complaints associated with using a mobile phone. Results: As many as 1800 questionnaires were sent. The response was obtained from 587 subjects aged 32.6±11.3 (48.9% women, 51.1% men); the age did not differ significantly between men and women. The subjects owned a cell phone for an average of 3 years. Majority of the respondents used the phone intensively, i.e. daily (74%) or almost daily (20%). Headaches were reported significantly more often by the people who talked frequently and long in comparison with other users (63.2% of the subjects, p = 0.0029), just like the symptoms of fatigue (45%, p = 0.013). Also, the feeling of warmth around the ear and directly to the auricle was reported significantly more frequently by the intensive mobile phone users, compared with other mobile phone users (47.3%, p = 0.00004 vs. 44.6%, p = 0.00063, respectively). Most symptoms appeared during or immediately after a call and disappeared within 2 h after the call. Continuous headache, persisting for longer than 6 h since the end of a call, was reported by 26% of the subjects. Conclusions: Our results show that the mobile phone users may experience subjective symptoms, the intensity of which depends on the intensity of use of mobile phones.

16

Metoda wzbudzanych SEM w analizie dokładności pomiarów pola elektromagnetycznego

75%

Długosz T.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2010

|

tom nr 5

181-184

PL

Omówiono wzajemne oddziaływanie anteny pomiarowej i obiektów materialnych. Zjawisko ma istotny wpływ na dokładność pomiaru, którego wynik może być obarczony nawet kilkudziesięcioprocentowym błędem. Należy o tym pamiętać i przy opracowaniu wyników pomiaru uwzględnić w postaci odpowiednich poprawek. Do analizy wykorzystano metodę wzbudzanych sit elektromotorycznych.

EN

This paper is devoted to mutual interactions between measuring antenna and conducting objects. The phenomena influences on measurements' accuracy which results can be loaded with few dozen percent error. It should be remembered and results of measurements should be taken into consideration as correction factors. Presented analysis use electromotive force induction method.

17

Skutki biologiczne ekspozycji na pola elektromagnetyczne– badania eksperymentalne

75%

Wiaderkiewicz R.

Podstawy i Metody Oceny Środowiska Pracy

|

2008

|

tom Nr 4 (58)

47--65

PL

Prezentowana praca jest przeglądem badań eksperymentalnych nad wpływem pól elektromagnetycznych na procesy biologiczne przebiegające w organizmach żywych. Przedstawiono metody stosowane do oceny oddziaływania pól elektromagnetycznych na poziomie komórkowym oraz dokonano analizy otrzymanych za ich pomocą wyników.

EN

The paper is a review of experimental studies on the effects of electromagnetic fields on biological processes in living organisms. It presents the methods used and analyses the results obtained with different experimental approaches.

18

Wpływ obcych pól magnetycznych w układach silnoprądowych

75%

Rajchert R.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

|

2001

|

tom z. 96

149--158

PL

W artykule opisano wpływ silnych pól magnetycznych występujących w systemach elektroenergetycznych na aparaturą energetyczną, a w szczególności na przekładniki prądowe. Przekładniki prądowe niskiego i średniego napięcia, pracujące w układach rozdzielni, są narażone na wpływy obcych pól elektromagnetycznych, które są przyczyną zmian ich parametrów.

EN

In the particular article, a description was given of the influence of strong electromagnetic fields on energy apparatuses and especially on current transformers in electro-energy systems. Low and high voltage current transformers, that work in switching station systems, are susceptible to the influence of foreign electromagnetic fields, which cause change in their parameters. In these transformers, it is difficult to ensure an EMC. Current transformers in current tracks can change their parameters depending on the size of the currents flowing in neighbouring tracks as well as the distance between these tracks. Errors in current and angle of the transformer can also undergo change. Overcurrent numbers can alter their sizes as well. Transformers with non functioning supply circuits can exhibit the flow of current in secondary circuits.

19

Hałas ultradźwiękowy : dokumentacja proponowanych wartości dopuszczalnych poziomów narażenia zawodowego

75%

Pawlaczyk-Łuszczyńska M. , Koton J. , Augustyńska D.

Podstawy i Metody Oceny Środowiska Pracy

|

2001

|

tom Nr 2 (28)

55--88

PL

Hałas ultradźwiękowy to hałas, w którego widmie występują składowe o wysokich częstotliwościach słyszalnych i niskich ultradźwiękowych (od 10 kHz do 40 kHz). Głównymi źródłami hałasu ultradźwiękowego w środowisku pracy są tzw. technologiczne urządzenia ultradźwiękowe niskich częstotliwości, takie jak: myjki, zgrzewarki, ultradrążarki, lutownice ręczne i wanny do cynowania (cynkowania) detali. Hałas ultradźwiękowy jest również emitowany przez sprężarki, palniki, zawory, narzędzia pneumatyczne oraz maszyny wysokoobrotowe, w tym strugarki, frezarki, szlifierki, piły tarczowe i niektóre maszyny włókiennicze. Hałas ultradźwiękowy działa szkodliwie na narząd słuchu (powoduje ubytki słuchu), a także wpływa ujemnie na układ przedsionkowy, co objawia się bólami i zawrotami głowy, zaburzeniami równowagi : nudnościami. Badania oddziaływań pozasłuchowych wykazały, że ekspozycja zawodowa na hałas ultradźwiękowy o poziomach powyżej 80 dB w zakresie częstotliwości słyszalnych i ponad 100 dB w zakresie niskich częstotliwości ultradźwiękowych wywołuje zmiany o charakterze wegetatywnym. Mierzone na stanowiskach pracy wartości poziomu ciśnienia akustycznego często przekraczają aktualne wartości najwyższych dopuszczalnych natężeń (NDN) hałasu ultradźwiękowego). Przekroczenia wartości dopuszczalnych rejestrowane są jedynie w pasmach tercjowych o częstotliwościach środkowych z przedziału od 10 kHz do 40 kHz. Mając na uwadze wyniki badań i analiz własnych, doniesienia literatury przedmiotu, zalecenia zawarte w normie ISO 9612:1997 i uwzględniając możliwości techniczne realizacji pomiarów zaproponowano: przyjęcie jako podstawy oceny narażenia na hałas ultradźwiękowy równoważnych poziomów ciśnienia akustycznego odniesionych do 8-godzinnego dnia pracy lub (wyjątkowo w przypadku oddziaływania hałasu ultradźwiękowego na organizm człowieka w sposób nierównomierny w poszczególnych dniach w tygodniu) tygodnia pracy oraz maksymalnych poziomów ciśnienia akustycznego, określonych w pa¬smach tercjowych ograniczenie oceny do zakresu pasm tercjowych o częstotliwościach środkowych z przedziału od 10 kHz do 40 kHz utrzymanie w ww. pasmach tercjowych dotychczasowych wartości dopuszczalnych ze względu na ochronę zdrowia ogółu pracowników (wartości NDN) i w odniesieniu do stanowisk pracy dla grup pra¬cowników o szczególnej wrażliwości (kobiety ciężarne, osoby młodociane), (DzU nr 79, poz. 513, 1998; DzU nr 14, poz. 545, 1996; DzU nr 85, poz. 500, 1990).

EN

Ultrasonic noise is defined as the broadband noise containing high audible and low ultrasonic frequencies (from 10 kHz to 40 kHz). The main sources of ultrasonic noise in the working environment are the so-called low frequency ultrasonic technological devices, including washers, welders, ultrasonic drills, soldering tools and galvanising pots. Ultrasonic noise is also generated by compressors, pneumatic tools and high-speed machinery such as planers, millers, grinders, circular saws and some textile machinery. Ultrasonic noise exerts adverse effects on the hearing organ thus producing hearing impairment, and affects the function of the vestibular system, which is manifested by headache, nausea., dizziness and disturbed balance. Investigations concerning non-auditory effects revealed that occupational exposure to ultrasonic noise at sound pressure levels above 80 dB in the high audible frequency range as well as above 100 dB within the low ultrasonic frequency range leads to autonomic system dysfunction. The sound pressure levels which occur at workplaces often exceed the current maximum ad¬missible intensity values (MAI) for ultrasonic noise, but the excess levels are recorded only in the 1/3-octave bands of the 10 kHz to 40 kHz frequency range. Taking into consideration the results of own ultrasonic noise measurements performed in the work environment, the literature reports on the effects of airborne ultrasound on humans, the recommendations of international standard ISO 9612 and the technical capacity for measure¬ments, the following proposals have been made: the assessment of occupational exposure to ultrasonic noise should be based on the equivalent of 1/3-octave band sound pressure levels normalised to a nominal 8-hour working day or 40-hour working week and of maximum 1/3-octave band sound pressure levelsthe range of assessment should be limited to 1/3-octave bands with the centre frequencies from 10 kHz to 40 kHz the current admissible values for workers health protection (MAI) and for the workers at particular risk i.e. pregnant women and juveniles should be maintained within the above mentioned 1/3-octave bands (DzU nr 114, poz. 545, 1996; DzU nr 85, poz. 500, 1990).

20

Pomiar wolnozmiennych pól elektromagnetycznych

75%

Chudorliński J. , Nowakowski A. , Spiralski L.

Elektronika : konstrukcje, technologie, zastosowania

|

2003

|

tom Vol. 44, nr 12

18-21

PL

Przedstawiono uwarunkowania związane z pomiarem niskoczęstotliwościowych pól elektromagnetycznych. Uzyskanie wyników pomiarów o zadanej dokładności wolnozmiennych pól elektromagnetycznych wymaga precyzyjnego ustalenia metodyki pomiarów oraz warunków, przy jakich pomiary są wykonywane. Przy opracowywaniu stanowisk pomiarowych należy uwzględnić techniczne uwarunkowania aparaturowe mające wptyw na wykonywany pomiar. Należy również brać pod uwagę dodatkowe czynniki takie jak zakłócenia zewnętrzne przyczyniające się do powiększenia błędu pomiarowego.

EN

In this article there are presented conditions of measurements of low frequency electromagnetic fields. In order to achieve given accuracy of low frequency electromagnetic fields measurements it is necessary to carefully establish methodology and conditions of measurements. When designing a measuring position one should take into consideration the influence of measuring Instruments on the measurement process and additional factors such as external measurements disturbance which increase the measurement error.