34
Test of resistance
Test level according to
to interference
IEC 60601
COMMENT: These guidelines do not necessarily apply in all situations. The spread of electromag-
netic waves is influenced by absorption and reflection from buildings, objects, and humans.
a)
The ISM bands (for industrial, scientific and medical applications) between 150 kHz and
80 MHz are 6.765 MHz to 6.795 MHz; 13.553 MHz to 13.567 MHz; 26.957 MHz to 27.283 MHz
and 40.66 MHz to 40.70 MHz.
b)
The compliance level in the ISM frequency bands between 150 kHz and 80 MHz and in the fre-
quency range 80 MHz to 2.5 GHz is designed to reduce the likelihood that mobile communica-
tion devices cause interference if they are unintentionally brought into the patient area. For
this reason a greater safety distance is recommended in these frequency ranges (factor 1.2
instead of 0.35).
c)
The field strengths of stationary transmitters, such as base stations for cellular phones and
land mobile radios, amateur radio stations and radio and TV broadcasts cannot be predicted
with accuracy. To assess the electromagnetic environment by fixed HF transmitters, a study of
the location should be considered. If the measured field strength exceeds the HF compliance
level at the location where the device is used, the device must be observed to ensure correct
functioning. Additional measures may be necessary, such as re-orienting or relocating the
external pacemaker.
d)
In the frequency range of 150 kHz to 80 MHz the field strengths should be less than 10 V/m.
Compliance
Guidelines for the electromagnetic
level
environment
P is the maximum rated power of
the transmitter in watts [W] accord-
ing to the information from the
transmitter manufacturer and d is
the recommended safe distance in
meters [m]
The field strength of stationary
transmitting devices must be mea-
sured on site
than the compliance level at all
frequencies
Interference can occur in devices
that have the following warning
sign.
b)
.
c)
and must be lower
d)
.