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Measurements of strengths of electric and magnetic fields near industrial radio‐frequency heaters
Author(s) -
Hietanen M.,
Kalliomäki K.,
Kalliomäki P.L.,
Lindfors P.
Publication year - 1979
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs014i06sp00031
Subject(s) - radio frequency , welding , magnetic field , range (aeronautics) , electric field , electric power , electric energy , materials science , electrical engineering , environmental science , power (physics) , physics , engineering , quantum mechanics , metallurgy , composite material
There are several hundred radio‐frequency (RF) heaters in industrial use in Finland. No exposure or performance standards have been established for this kind of device in our country. This paper describes measurements of strength of electric and magnetic fields near 35 plastic‐welding machines, all operating at 27 MHz at nominal power outputs that range from 0.5 to 35 kW. Approximately 70% of the heaters radiated RF energy at strengths that exceeded common standards (200 V m −1 , 0.5 A m −1 ). The Finnish proposed safety standard (60 V m −1 , 0.2 A m −1 ) was exceeded in 80% of the cases. The results indicate that both electric and magnetic fields should be measured independently.