Job Card Cal A053 - Mas Non-Linearity Calibration - GE Senographe DS Manual

GE Healthcare
Revision 1

Job Card CAL A053 - mAs Non-linearity Calibration

1 SUPPLIES
None
2 TOOLS
Flat field phantom
3 REQUIRED EFFORT
Personnel: 1 Field Engineer
Time: 10 minutes
4 SAFETY PRECAUTIONS
The procedures in this Job Card produce X-rays. Ensure that you take appropriate precautions when
operating with X-rays (for example, stay behind the radiation screen during an X-ray exposure).
5 PREREQUISITES
None
6 PROCEDURE
6-1 Presentation
The object of mAs non-linearity calibration is to compensate for the non-linearity of exposure delivered
by the Generator at low mAs values, as used in AOP pre-exposure operations.
This procedure measures pre-exposure linearity deviation, and stores a correction factor in the X-ray
Console menu, to be applied to the mAs value of all AOP exposures.
The correction factor is automatically calculated as: MASPRE CORR = S
S are the signals measured in the 100 mAs image and the 4 mAs image respectively.
4
6-2 Procedure
1. Install the Flat Field Phantom on the Bucky.
2. Install the paddle without compressing the phantom.
3. From the X-ray Console menu, enter the SET UP/GENE/INSTAL/GENE/AOP/APOLLO/CALIB/
mAsPRE/CALIB menu.
4. Press CALIB.
5. Press the Exposure button
(about 20 seconds), then CALIBRATION END appears on the X-ray Console display. Release the
Exposure button
and MoMo/28 kV/100 mAs.
6. Press SETUP once, then press PARAM.
7. Verify that the value displayed for MASPRE CORR is within the limits given below (Acceptable val-
ues).
8. Perform a checksum (SETUP/SETUP/SETUP/SETUP/SETUP/SETUP/CKSUM/CKSUM).
JC-CAL-A-053.fm
Service Information and Procedures Class A 2385072-16-8EN
on the X-ray Console and hold it down. Two exposures are taken
. Parameters for the two exposures are automatically set to MoMo/28 kV/4 mAs
Job Card CAL A053 - mAs Non-linearity Calibration
Page no. 1725
Senographe DS
Chapter 9
/ (25 x S , where S
100 4)
and
100
Chapter 9