Specifications

B-field Exposure From Induction Cooking Appliances 24
4.2 Time- and Frequency-Domain Characterization of the Induction Cookers
4.2.1 Time-Domain Characterization
Measurements The alternating magnetic fields generated by the induction cookers were mea-
sured with the Narda probe ELT-400. The analog output signals of the probe were recorded with
a digital oscilloscope (Agilent 54622D mixed signal oscilloscope). The B-fields were measured
in front (measuring distance 1 cm) of the largest hobs: hobs 1, 2 and 1 for appliances 1, 2 and
3, respectively. For each experiment the standard pot 3 with lid was centered on the hob and
filled with 3 liters of tap water. The time-domain signals corresponding to appliances 1, 2 and
3 are given in Figures 17, 18 and 19, respectively.
Figure 17: Time-domain signals of the alternating magnetic fields generated by ap-
pliance 1. Graphs a) and b) correspond to the heat settings 4 and P. The fundamental signal
frequencies are, respectively, 41.7 kHz and 17.5 kHz. The signal rms-value increases approxi-
mately by a factor of 5 for heat settings from 4 to P. Graphs c) and d) correspond to the heat
settings 4 and P and show a signal envelope with a frequency of 100 Hz that remains constant
for all heat settings. Graphs e) and f) correspond to the heat settings 1 and 3. For heat settings
1 to 4, the signal is pulse-width modulated, with a frequency of 0.5 Hz.