T4 EEG Amplifier User Manual
49
Immunity Test
EN 60601 Test Level
Compliance Level
Electromagnetic Environment Guidance
Portable and mobile RF communications
equipment should be used no closer to any
part of the T4, including cables than the rec-
ommended separation distance calculated
from the equation applicable to the frequency
of the transmitter.
Recommended separation distance
RF Common mode/
Conducted Susceptibility
EN 61000-4-6
3 Vrms
150 kHz to 80 MHz
3 Vrms
d = [3.5/V]
√
P
= 1.2
√
P
Note: using unshielded input leads
c
Radiated RF Electromag-
netic Fields
EN 61000-4-3
3 V/m
80 MHz to 2.5 GHz
3 V/m
d = [3.5/E]
√
P : 80 MHz to 800 MHz
= 1.17
√
P
d = [7/E]
√
P : 800 MHz to 2.5 GHz
= 2.33
√
P
Note: using unshielded input leads
d
Where P is the maximum output power rating
of the transmitter in watts (W) according to
the manufacturer and d is the recommended
separation distance in meters (m).
Field strengths from fixed RF transmitters, as
determined by an electromagnetic site sur-
vey
a
, should be less than the compliance level
in each frequency range
b
.
Interference may occur in the vicinity of equip-
ment marked with the following symbol:
NOTE 1. At 80 MHz and 800 MHz, the higher frequency range applies.
NOTE 2. These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection
from structures, objects and people.
a
Field strength from fixed transmitters, such as base stations for radio (cellular/cordless) telephones and land mobile radios,
amateur radio, AM and FM radio broadcast and TV broadcast cannot be predicted theoretically with accuracy. To assess the
electromagnetic environment due to fixed RF transmitters, an electromagnetic site survey should be considered. If the meas-
ured field strength in the location in which the T4 is used exceeds the applicable RF compliance level above, the T4 should be
observed to verify normal operation. If abnormal performance is observed, additional measures may be necessary, such as
re-orienting or relocating the T4.
b
Over the frequency range 150 kHz to 80 MHz, field strengths should be less than 3 V/m.
c
The immunity levels for conducted RF are for unscreened input electrode leads 1 m in length and worse-case coupling, in-
cluding any resonances across the frequency band. The interference is less when the coupling plane of the interference
source is not in the same plane as the electrode leads.
d
The immunity levels for radiated RF are for unscreened input electrode leads 1 m in length and worse-case coupling, includ-
ing any resonances across the frequency band. The interference is less when the polarisation plane of the interference source
is not in the same plane as the electrode leads.