Checking X-Ray Tube High Voltage, Tube Currrent And Mas Values; Tube Current Reduction - Siemens MOMMOMAT 1000 Installation And Start-Up Instructions Manual

10 - 2
3.
4.
NOTICE
5.
6.
NOTICE

Checking X-ray tube high voltage, tube currrent and mAs values

1.
2.
3.
4.

Tube current reduction

NOTICE
Mammomat 1000/3000
Installation and Start-Up
Connect oscilloscope to P.C. board D705 as follows:
•
Channel 1 to measuring point "KVIST
•
Channel 2 to measuring point "MAIST
•
Trigger at measuring point "KVE" (start with high voltage "ON"), rising edge.
•
Twist the measuring leads and connect their grounding braids to measuring
point "0 VA".
Connect service PC to circuit board D702 using the connection cable.
Switch S3 on circuit board D702 must be set to upper position.
Start service program, see Chapter 20 "Appendix".
Check the anode menu for correct selection (tungsten anode enabled or disabled,
depending on which type of X-ray tube the customer has choosen). See Service
Program Instructions RX B7-230.114.01. ... .
It is possible to select tungsten anode, even if the customer does
not have this option. However, the 50 µm Rh filter will then be
missing.
System "ON".
Set the "cassette loaded" switch to "OFF" with the service PC program:
Configuration - Miscellaneous - Cassette loaded check.
Trigger test exposures with the following exposure values and check the kV
values and tube current characteristic on the oscilloscope (see oscillograms).
The accuracy of the kV is
For mA values < 50 mA, the accuracy of the kV is 5% plus
5 ms.
The tube current must rise quickly to the set value at the beginning of the expo-
sure and run linearly during the exposure, however, not when TCR is running.
The accuracy of the mAs product must be 10%.
Replace the jumper previously removed.
In MAMMOMAT, the tube current reduction is factory-set to "ON"
(see Chapter 12 "Further programming" and test certificate). In
this way, the tube current is reduced to approximately 50 mA at
the start of the exposure during the time programmed in Chapter
12 "Further programming". The tube current reduction is effective
only in IONTOMAT mode with Bucky.
Register 3
Checks with high voltage
(actual value)
(actual value)
5% plus 1.5 kV during the first 5 ms of the exposure.
SP B7-230.033.07
Rev. 03 11.99
" (1 V= 5 kV).
" (1 V= 40 mA).
2 kV during the first
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