Abstand zw. exponiertem Objekt und Expositionsquelle
The RF-absorbing material had a return loss better than -20 dB above 450 MHz. The furniture in the room was made from wood.
The mobile phone was held by a plastic holder with the monopole antenna positioned horizontally above the head of the subject sitting in an armchair.
Eine Scheinexposition wurde durchgeführt.
The EEG was recorded in three sections of 10 min each with exposure in the middle section. The neuropsychological tests were performed on subsequent days with or without exposure. The tests were carried out incompletely double-blind. Interference of the exposure field with the EEG recording was avoided by selecting a higher sampling rate at 500 Hz.
Interfering fields were measured in several cycles with a total duration of several hours with the aid of various broadband antennas. The magnetic field measured between 5 Hz and 10 MHz was below 326 nT at 50 Hz. The electric field measured between 9 kHz and 3 GHz was below 25 mV/m with short term peaks at 70 kHz and between 100 and 200 MHz.
Mess- und Berechnungsdetails
The resulting field distribution in the test room was simulated using a local numerical program. The peak value of the electric field strength depending on the radial distance from the antenna was measured in an anechoic chamber using two identical calibrated monopole probes. The antenna distance from the head was adjusted not to exceed the applicable limit of DIN/VDE 0848 being 41.4 V/m at 914 MHz.