Emi Reduction - GE Healthcare Brivo XR118 Service Manual

GE H
EALTHCARE
D 5461425-8EN, R
IRECTION
Section 7.0

EMI Reduction

7.1 EMI Check Procedure
If the RCN in QAP always failed or row correlated noise (RCN) type of artifacts found in image,
following test need to be done to double check the EMI.
1.) EMI check purpose
2.) EMI check setup
3.) EMI check procedure
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6
EVISION
EMI check is used to check whether EMI is present or not during exposure from target X-ray
system. An interference maybe from following equipment in the field, an EMI check is needed
to decide whether to switch EMI on or off in utility setting.
- Moving bucky
- Ion Chamber
- Generator is under table and largest mA is large than 100mA
- Surrounding 220V or 380V power cable on site
a.) If Ion Chamber is present, choose AEC exposure.
b.) If moving bucky is present, turn bucky on for exposure.
c.) Detector in table tray or wallstand tray.
d.) Exposure techniques, 50KV, 10x10 cm FOV, Choose maximum mA used by target
system.
For AEC test, mS is decided by system.
For non-AEC test, choose 25mS exposure.
a.) Put detector in table tray
b.) Start exam in workstation, and click prepare button
c.) Choose the exposure techniques defined in test setup.
d.) After auto-sensing ready, take an exposure.
e.) After getting the image, adjust the image to proper Window width and window level.
Check whether an band is observed in image. Or an EMI pattern is observed outside X-
ray FOV.
f.) There are 4 locations for a detector in tray by rotating the detector 90 Degree in table tray
clockwise. For each location, repeat step 2 to step 5 twice.
g.) Put detector in wallstand tray and repeat step 2-step 6.
h.) There are totally 8 or 16 images, If any image show band or EMI pattern, It means an EMI
is present during exposure or acquisition. Suggest to turn EMI on. Note: since an EMI is
present during exposure, in EMI on mode, only positioning patient, then press prepare
button and take exposure.
Section 7.0 - EMI Reduction
B XR118 S M
RIVO ERVICE ANUAL