Siemens MOBILETT Plus HP Maintenance Instruction

Siemens AG SPR8-220.101.04.03.02 MOBILETT Plus HP
07.05 CS PS 24
Inspection and Maintenance 45
Page 45 of 64
Medical Solutions
2.8 Test of mAs accuracy
Requirement
The actual product of the exposure time and tube current (mAs) must match the displayed
value within the limits established by Siemens.
Required measurement devices:
Storage oscilloscope with a measurement accuracy of ± 2.5 %.
Procedure:
• Close the collimator.
• Connect the oscilloscope to test points ”MAPOS” and ”GND” on board D1.
• Switch on the X-ray system and the oscilloscope and wait approximately 5 minutes un-
til the units have stabilized.
Example: Calculating the mAs
Fig. 22:
The mA signal is built up of a series of pulses. To get the real tube current, it is necessary
to use an oscilloscope with the possibility of showing a part of the time sweep expanded
so that each current pulse is clearly visible. Then the current can be measured according
to the figures above.
The mAs value can be calculated using the information displayed on the oscilloscope.
Surface ”A” corresponds to the mAs value.
mAs = Tube current x exposure time
mAs = 340 mA x 0.006 s = 2.0 mAs

Siemens MOBILETT Plus HP Specifications

General

Brand	Siemens
Model	MOBILETT Plus HP
Category	Medical Equipment
Language	English