Measuring The Filament Nominal Value; Setting The Tube Current For The Exposure - Siemens POLYMOBIL Plus Service Instructions Manual

Measurements

Measuring the filament nominal value

The filament nominal value is set at the factory and should not be changed.
The filament nominal value can be measured on D915 at TP "JRS" and "GND" with the
DVM and is 1.5 V
NOTICE

Setting the tube current for the exposure

The tube current must be reset for each tube.
Proceed as follows:
•
Connect the oscilloscope to D915 at TP "JR", "IH" and "GND".
•
Set 60 kV, 10 mAs on POLYMOBIL Plus and release an exposure.
The oscillogram must appear like the one in Fig. 13.
Fig. 13
Actual tube current valueCH1: D915 test point "JR"
Actual fil. current value CH3: D915 test point "IH"
If this is not the case, adjust P5 on D915 until there is minimal current overshoot at the
beginning of the exposure.
The standby heating of the exposure is set via P5 (
Fig. 13 shows the correct setting.
In Fig. 14 the standby heating is set too high.
In Fig. 15 the standby heating is set too low.
Siemens AG
Medical Engineering
±
4% in standby.
If this value is changed, the nominal values for preparation and
exposure are also affected.
SPR8-125.061.02
Rev. 01
IH
Page 13 of 20
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, IH
POLYMOBIL Plus
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