GE Vivid P3, Руководство по обслуживанию

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GE H
EALTHCARE
PROPRIETARY TO GE
D
IRECTION
5344303-100, R
EVISION
3 V
IVID
P3 S
ERVICE
M
ANUAL
Chapter 2 Pre Installation 2-5
2-2-3 EMI Limitations
Ultrasound machines are susceptible to Electromagnetic Interference (EMI) from radio frequencies,
magnetic fields, and transient in the air wiring. They also generate EMI. The Vivid P3 complies with
limits as stated on the EMC label. However there is no guarantee that interface will not occur in a
particular installation.
Possible EMI sources should be identified before the unit is installed.
Electrical and electronic equipment may produce EMI unintentionally as the result of defect.
These sources include:
• medical lasers
• scanners
• cauterizing guns
• computers
• monitors
• fans
• gel warmers
• microwave ovens
• light dimmers
• portable phones
• Lift
The presence of a broadcast station or broadcast van may also cause interference.
See Table 2-5 for EMI Prevention tips.
Table 2-5 EMI Prevention/abatement
EMI Rule Details
Be aware of RF sources
Keep the unit at least 5 meters or 15 feet 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 all screws, RF
gaskets, covers, 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 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.
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. Or, if a label has been found in such a position, move the label.
Use GE specified harnesses
and peripherals The interconnect cables are grounded and require ferrite beads and other shielding. Also,
cable length, material, and routing are all important; do not change from what is specified.
Take care with cellular phones Cellular phones may transmit a 5 V/m signal; that could cause image artifacts.
Properly dress peripheral
cables
Do not allow cables to lie across the top of the card cage or hang out of the peripheral bays.
Loop the excess length for peripheral cables inside the peripheral bays. Attach the monitor
cables to the frame.