GE Voluson i BT06, Service Manual

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GE V
OLUSON
i / V
OLUSON
e
D
IRECTION
KTI106052, R
EVISION
10 S
ERVICE
M
ANUAL
Chapter 2 - Site-Preparation 2-3
2-2-3 EMI Limitations
Ultrasound systems are susceptible to Electromagnetic Interference (EMI) from radio frequencies,
magnetic fields, and transients in the air or wiring. Ultrasound machines also generate EMI. The
Voluson i / Voluson e complies with limits as stated on the EMC label. However, there is no guarantee
that interference will not occur in a particular installation.
Electrical and electronic equipment may produce EMI unintentionally as the result of a defect.
Sources of EMI include the following:
• medical lasers
• scanners
• cauterizing guns
• computers
• monitors
• fans
• gel warmers
• microwave ovens
• portable phones
• broadcast stations and mobile broadcasting machines
NOTICE
!! NOTICE:
Possible EMI sources should be identified before the unit is installed, and should not be on the same
line as the ultrasound system. A dedicated line should be used for the ultrasound system.
Table 2-4 EMI Prevention/ Abatement
EMI Rule Details
Be aware of RF sources.
Keep the unit at least 5m (16.4 ft) away from other EMI sources. Special shielding may be
required to eliminate interference problems caused by high frequency, high powered radio
or video broadcast signals.
Ground the unit.
Poor grounding is the most likely reason a unit will have noisy images.
Check grounding of the power cord and power outlet.
Replace and/or reassemble
all screws, RF gaskets,
covers and cores.
After you finish repairing or updating the system, replace all covers and tighten all screws.
Any cable with an external connection requires a magnet wrap at each end.
Install the shield over the front of the card cage. Loose or missing covers or RF gaskets
allow radio frequencies to interfere with the ultrasound signals.
Replace broken RF gaskets.
If more than 20% or a pair of the fingers on an RF gasket are broken, replace the gasket.
Do not turn ON the unit until any loose metallic part is removed and replaced, if required.
Do not place labels where
RF gaskets touch metal.
Never place a label where RF gaskets meet the unit. Otherwise, the gap created will permit
RF leakage. In case a label has been found in such a location, move the label to a different,
appropriate location.
Use GE-specified harnesses
and peripherals.
The interconnect cables are grounded and require ferrite beads and other shielding.
Cable length, material, and routing are all important; do not make any changes that do not
meet all specifications.
Take care with cellular
phones.
Cellular phones may transmit a 5 V/m signal that causes image artifacts.
Properly address peripheral
cables.
Do not allow cables to lie across the top of the system.
Loop any peripheral cable excess length into one bundle.