The magnitudes reported for time-varying (AC) measurements were obtained by vector summation of the fields recorded at the 3 perpendicular axes (x,y,z).

The measurements reported for each environment correspond to the frequency with maximum amplitude in a spectrum of up to 600 Hz. All spectrums had maximums at 60 Hz and they were mainly composed harmonics of that frequency. The attenuation values are referenced to the average of readings made on the center of the room with no nearby electricity consuming devices.