Siemens SIREMOBIL Compact L - Supplement, Measuring the tube current; Measuring the tube current

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Siemens AG SPR2-130.061.02 Page 1 of 2 SIREMOBIL Compact
Medical Solutions Rev. 11 09.04 CS PS 24 System Manual
Supplement, Measuring the tube current 8
• Switch OFF SIREMOBIL Compact.
• Remove jumper X97 from board D1.
• Connect the mA measuring device at D1.X39 and D1.X40.
• Switch ON SIREMOBIL Compact.
• Release radiation and read the overall current.
• Read out the kV value produced while the current is being measured.
Calculate the tube current as follows:
e.g.:
At 110kV, an overall current of 5.275 mA is measured.
X-ray radiation!
See Chapter 1, Safety Information.
Protect yourself against radiation exposure. Wear a lead apron.
When measuring the tube current, the distribution current must
be derived from the measured value. The distribution current
depends upon the kV and is calculated according to Ohm's law.
The distribution resistance is 400 MOhm.
tube current [mA] = overall current [mA] -
high voltage [kV]
distribution resistance [MOhm]
tube current [mA] = 5.275 [mA] -
110 [kV]
= 5.275 [mA] - 0.275 [mA] = 5.0 [mA]
400 [MOhm]
WARNING
NOTE