GE Vivid 7, Руководство по обслуживанию

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GE H
EALTHCARE
D
IRECTION
FC091194, R
EVISION
11 V
IVID
7 S
ERVICE
M
ANUAL
Chapter 6 - Service Adjustments 6 - 7
6-7-3 Front-End Alignment Procedure
1.) Disconnect all connected probes.
2.) Turn on the Vivid 7.
3.) Press
CONFIG
(
F2
) and log on as adm , see 4-2-4 "Log On to the System as ‘ADM’" on page 4-12 .
4.) Select
System
5.) Select
DC Offs. Cal
to start the DC Offset calibration of the Beam Formers (Front-End Alignment).
6.) Wait for the calibration to take place.
Front-End Alignment Description
- Each A/D converter will get 0V input (by setting ATGC to minimum).
- One by one channel will be digitized and the result put in the IQ buffer on the RFT board.
- The BEP will then read the IQ buffer and computes a value per channel. These computed
values are compared to an upper/lower limit.
- If all read values are ok, the message PASSED will appear. If values exceeding the limits are
read, the system will prompt you with FAILED and a message will tell you which BF board is
bad.
- The resulting offsets for each channel are stored in a file on the Back-End Processor’s hard
disk.
- The values can be plotted in a diagram
Show graph
).
7.) When finished, select
Show Graph
.
Wavy line signifies system has been calibrated. See Figure 6-3 "DC Calibration of the Beam Former
AD-converters Passed" on page 6-8 .
A Straight line signifies that the system has not been calibrated and can be the cause of image
quality issues.
Figure 6-2 Calibration Dialog
Channel Control
DC Offs. Cal
Cal. Reset
Show graph