Magnetic emission ranking of electrical appliances. A comprehensive market survey.
Over the last decades emissions of magnetic fields from electric appliances have considerably changed. Based on a comprehensive market survey it could be shown that today magnetic emissions are usually characterised by complex frequency spectra while single-frequency emissions have become rare. Therefore, spectral assessment procedures play a critical role. Compared to frequency-weighted equivalent magnetic induction, rms values may underestimate emissions up to two orders of magnitudes. Therefore, rms measurements are not suitable and emission-ranking lists of devices need revision. Surface hot-spot measurements at nominal load conditions and 230 V/50 Hz supply involved 1146 new electrical devices of 166 different categories. High emissions were not rare. Magnetic emissions of devices of 73 different categories exceeded reference levels up to almost two orders of magnitudes above reference levels. Maximum values were higher than reported so far. Magnetic emissions were high enough to make even conformity with existing basic restrictions not self-evident.
Leitgeb
N
N
Institute of Clinical Engineering and European Notified Body of Medical Devices, Graz University of Technology, Inffeldgasse 18, Graz, Austria. norbert.leitgeb@tograz.at
Cech
R
R
Schröttner
J
J
Lehofer
P
P
Schmidpeter
U
U
Rampetsreiter
M
M
D004574:Electromagnetic Fields; D004781:Environmental Exposure / Q000032:analysis / Q000517:prevention & control* / Q000592:standards; D006794:Household Articles; D006801:Humans; D011834:Radiation Monitoring / Q000379:methods*; D018570:Risk Assessment