GE Brivo OEC 715 Service Manual page 221

Brivo OEC 715/785/865 Mobile C-Arm X-Ray Product Service Manual
3. Power on the system. Set the exposure mode and parameter to check to the mA measured
values. The measured values should be in the range of the form below. The measured values
include mA real value and mA leakage from tube inside as below:
Exposure mA_real =mA_measure –kV/800
The error of Exposure mA_real value should be within ±10% ranges.
Otherwise, mA calibration procedure should be performed until all the mA_measure values meet the
requirement in the list.
Exposure mode
Low Dose 2mA@80KVp
Fluoro
Normal Fluoro 0.1mA@80KVp
4mA@110KVp
HLF 6mA@110KVp
4.5mA@110KVp (In Dose Group
HLF 50)
4. mA accuracy of Digital Spot:
Measure the voltage of TP7 (MA-SMP) on MCB board with oscilloscope:
Formula A: Exposure mA_real =Sample Voltage (TP7) (unitV)*1000/400ohm (For power is less than
1320w)
Formula B: Exposure mA_real =Sample Voltage (TP7) (unitV)*1000/200ohm (For power is more than
1320w)
The error of Exposure mA_real value should be within ±10% ranges.
Set the exposure mode and parameter to check to the voltage (TP7) values. The voltage of TP7
should be in the range of the form below. Otherwise, mA calibration procedures should be
performed until all the voltage values meet the requirement in the list.
Exposure Exposure
mode mA_real
Digital 6.4mA@80kVp
Spot
16mA@110kVp
10mA@110KVp
4-10
Exposure mA_real
Voltage
Voltage (TP7)
(TP7)
maximum (V)
minimum (V)
-2.82
-3.52
-4.40
mA_measure Min
(mA)
1.90
0.19
3.78
5.52
4.17
-2.30 For 100/110V/120V and
200V/220V/230V/240V input
Set 3.2mA@80KVp in mainframe control
panel
Use formula A
-2.88 For 200V/220V/230V/240V input
Set 4mA@110KVp in mainframe control
panel
Use formula B
-3.60 For 100/110V/120V input
Set 4mA@110KVp in mainframe control
panel
Use formula A
mA_measure Max (mA)
2.30
0.21
4.54
6.75
5.10
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