Emi Limitations - GE LOGIQ E9 Service Manual

GE
D 5573152-100, R
IRECTION
2-2-3

EMI limitations

Ultrasound machines are susceptible to Electromagnetic Interference (EMI) from radio frequencies,
magnetic fields, and transients in the air or wiring. Ultrasound machines also generate EMI. The
LOGIQ E9 complies with limits as stated on the EMC label. However there is no guarantee that
interference will not occur in a particular installation.
Possible EMI sources should be identified before the LOGIQ E9 is installed.
Electrical and electronic equipment may produce EMI unintentionally as the result of a defect. These
sources include:
• medical lasers,
• scanners,
• cauterizing guns,
• computers,
• monitors,
• fans,
• gel warmers,
• microwave ovens,
• light dimmers,
• portable phones.
The presence of a broadcast station or broadcast van may also cause interference.
See:
Table 2-5
Table 2-5
EMI RULE
Be aware of RF sources
Ground the LOGIQ E9 Poor grounding is the most likely reason a LOGIQ E9 will have noisy images. Check
Replace all screws, RF
gaskets, covers, cores
Replace broken RF
Do not place labels
where RF gaskets touch
Use GE specified
harnesses and
peripherals
Take care with cellular
Properly dress
peripheral cables
. 2
EV
for EMI Prevention tips.
EMI prevention/abatement
Keep the LOGIQ E9 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.
grounding of the power cord and power outlet.
After you finish repairing or updating the LOGIQ E9, replace all covers and tighten all
screws. Any cable with an external connection requires a magnet wrap at each end.
Install the Card Rack cover over the Card Rack. Loose or missing covers or RF
gaskets allow radio frequencies to interfere with the ultrasound signals.
If more than 20% or a pair of the fingers on an RF gasket are broken, replace the
gaskets
gasket. Do not turn on the LOGIQ E9 until any loose metallic part is removed.
Never place a label where RF gaskets meet the LOGIQ E9. Otherwise, the gap
created will permit RF leakage. Or, if a label has been found in such a position, move
metal
the label.
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.
Cellular phones may transmit a 5 V/m signal; that could cause image artifacts.
phones
Do not allow cables to lie across the top of the Card Rack or hang out of the peripheral
bays. Loop the excess length for peripheral cables inside the peripheral bays. Attach
the LCD cables to the frame.
Chapter 2 Site preparations
LOGIQ E9 S
DETAILS
M
ERVICE ANUAL
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