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Neuro-Audio (Technical Manual)
18
3.2. The voltage between the phase (hot) and ground sockets must be stable
(230 V for Europe/110 V for US (country specific). It is the same voltage
as in item 3.1 (see above) with a deviation of max 5 V.
If the measured voltage is much less than 230 V Europe/110 V US,
the ground is not connected to true ground. Even though you can see
the lead inside the wall outlet this lead is not connected to the true ground.
3.3. The voltage between zero (neutral) and ground it must be at about 0 V.
If the measured voltage differs much from 0 V, it means that the ground
is not connected to the true ground. Even though you can see the lead
inside the wall outlet this lead is not connected to the true ground.
The ABR equipment must be connected to a proper true ground to provide safe
operation and obtain good ABR recording and correct test results.
To obtain the best ground, a separate ground dedicated to ABR recording site should
be wired and connected directly to the true ground using at least three earth rods.
The best test site for ABR recordings is:
1. The electric magnetic shielded room (it is also soundproof as well).
2. Separate ground only for ABR recording.
Besides, follow these recommendations to exclude other factors except electrical
noise:
1. Turn off the light and other electrical equipment not being used as the patient will
be as antenna and pick up electrical interference.
2. Conduct testing in a soundproof room.
3. Do not let other patients/visitors come in the room as they may disturb the patient
trying to relax.
2.4. Unpacking and Checking Delivery Set
If the box with the digital system was under the conditions of excessive moisture
or low temperature which differs significantly from the working conditions, place
it in the room with normal conditions and leave there for 24 hours.
Unpack the box and take out the components of the digital system. The delivery set
should coincide with the packing list.
The computer equipment packed in separate boxes should be opened according
to the user and technical manuals for these products.