Transcript here - RAD 2012

NON-IONIZING RADIATION MEASUREMENTS IN
VOJVODINA
Istvan Bikit, Dusan Mrda,Nebojsa Krstic, Nikola Jovancevic, Mile
Ugarcina, Slavko Todorovic
Department of Physics, Faculty of Sciences, University of Novi Sad,
21000 Novi Sad, Serbia
-The main goal of measurements : Exploration of the existing situation
in environment of Vojvodina province, regarding to electromagnetic
field levels in the vicinity of sources of non-ionizing radiation, as well as
comparison of these values with current legislative
-Also, this exploration should contribute to the analysis of possible
ways of future reduction of electromagnetic field intensity in the
environment
***
-The corresponding measurements are performed in several cities (radio
emission antennas are measured in 8 cities ,Cellular phone network stations
and transformer stations in 10 cities and high voltage power transmission
lines in 12 cities )
-Low-frequency measurements (range: 5 Hz – 100 kHz) covered transformer
stations and high-voltage power transmission lines
-Within the high-frequency range (1 MHz – 3 GHz ) the measurements were
related to cellular phone network stations and radio emission antennas
- Measurements of electric field strength and magnetic induction are realized
at several measurement points around each source of non-ionizing radiation,
using equipment for broadband and frequency-selective measurements
● Low-frequency range
- the measurements of electric field strength and magnetic induction are
performed by Portable field meter PMM 8053B ( Narda, Italy ) using
spectrum analyzer EHP-50C (5 Hz – 100 kHz)
spectrum analyzer EHP-50C
-The probe EHP-50C allows
measurements of electric or
magnetic field components along
three spatial axes
Portable field meter PMM 8053B
-The probe was mounted on tripod
made of non-conducting material
and connected to the portable field
meter by 5m long optical-fiber
cable, avoiding the perturbation of
electromagnetic field by operator
- Near the transformer stations and high voltage power transmission lines, the
dominant frequency of electromagnetic field of 50Hz, as well as several
harmonics are detected
-The measured values of electric and magnetic field on these frequencies
were found for the probe position of 1m above ground
● High-frequency range
- The broadband measurements of
electric field strength in highfrequency range are performed by
Portable field meter PMM 8053B and
probe EP-300 (100 kHz – 3 GHz)
- Frequency-selective measurements in
the high –frequency region are realized
by RF Spectrum Analyzer-SPECTRAN
HF 2025E (AARONIA, Germany) and
Radial Isotropic Broadband antenna –
OmniLog 90200 (700 MHz – 2.5 GHz)
- The measurements are performed at
1.5 m height above ground on different
distances from the non-ionizing sources
● Results
● Cellular phone network stations
- Maximal values from broadband measurements, found for all locations,
were below 2.1 V/m.
The average values for each location
of electric field strength from
broadband measurements
The maximal values of electric field
strength at certain frequencies
( frequency-selective measurements)
Reference values
Frequency
[MHz]
Electric field strength
900
16.5
1800
23.3
2000 - 10 000
24.4
[V/m]
- average values of electric field strength were below 1.2 V/m.
- Relatively small value of standard deviation of about 85% indicates a
reasonable uniformity of emissions of cellular phone network stations on
the Vojvodina territory.
● Radio emission antennas
-The radiation of radio emission antennas was measured in 8 cities,
where one antenna was selected in each city. The broadband technique is used.
The maximal values of electric field
strength(broadband measurements)
Distribution of average values of electric field
-These distributions, together with very small values of standard deviations show that
this category of electromagnetic radiation is very uniform in the Vojvodina region.
●High voltage power transmission lines
-The electromagnetic radiation of high voltage power transmission lines was
investigated in 10 cities in Vojvodina
-The values of electric field strength and magnetic induction were covered
by measurements
Distribution of average values of
electric field strength
Distribution of average values of
magnetic induction
- The average values of electric field varied significantly among locations,
while the variations of magnetic induction were relatively small
●Example of electromagnetic field measurements of 220 kV high
voltage power transmission lines No. 127/11 in Novi Sad
- Measurements of electric field strength and magnetic induction are performed
at 1m above ground in 21 points along direction perpendicular to the high
voltage power transmission lines
Measurement points below high voltage power transmission lines
Distribution of electric field
Distribution of magnetic field
●Transformer stations
- Electromagnetic radiation of transformer stations is measured in 12 cities in Vojvodina.
Average values of electric
field for transformer stations
Average values of magnetic
field for transformer stations
-Very high value of electric field strength is found at one measurement
point around transformer station in Vrbas, under the high voltage power
transmission lines, where the transmission lines are connected to the
transformer station
-This value, which is mainly caused by transmission lines, reached 58% of
reference value according to current legislative in Serbia
-At the other locations, the measured maximal values of electric field were
much lower, and did not exceed 0.34% of reference value
Reference values
For f = 50 Hz =0.05 kHz → E REF.= 2000 V/m
-The magnetic induction values were much more uniformly distributed
than electric field values
Conclusions
-the described system of measurement can provide rough insight in distribution
of electromagnetic field intensity on the Vojvodina territory
-the amount of acquired data is not enough for formulation of statistically
significant conclusions.
-In recent time the mobile comunications develops intensively, so the cellular
phone network stations are perceived in public as the major sources of nonionizing radiation in the environment
-However, this research shows that all sources of non-ionizing radiation ,
should be considered with equal and increased attention, having in mind that
the health effects of non-ionizing radiation are not well known.