Chapter 9
Page no. 1704
JC-CAL-A-046.fm
GE Healthcare
Senographe DS
Revision 1
Service Information and Procedures Class A 2385072-16-8EN
Job Card CAL A046 - Half-Value Layer Measurement
other configurations.
8
PROCEDURE
! Notice:
The dose values to be entered in the X-ray Console menu must be expressed in mGy.
-
If your dosimeter displays dose values in mR, divide the reading by 114.2 to obtain mGy.
-
If your dosimeter displays dose values in
μ
Gy, divide the reading by 1000 to obtain mGy.
Note that you must use the format
x.xxx E+0
to enter a dose value
x.xxx
.
1. Ensure that paddle decompression at end of exposure is set to “NO”. In the X-ray Console menu, set:
MEDICAL/DECOMP/DECOMP/NO
2. Place the standard 19 cm x 23 cm compression paddle
upside down
as close as possible to the X-
ray tube.
3. Remove the Bucky or breast support; place the Dosimeter Support with Radiation Protection Plate on
the image receptor.
4. Place the dosimeter with 6M chamber on
the
high position
of the Dosimeter Support
(the source-to-
dosimeter distance SDD = 592mm).
5. Select the 9 x 9 collimator format; verify using the light beam that the 6M ionization chamber is fully in
the beam.
6. In the HVL/Yield calibration menu on the X-ray Console, enter the path corresponding to the Large
Focus (LF) configuration you are measuring:
The Senographe automatically selects the acquisition parameters (see table above).
7. Take the calibration exposure (press the Exposure button
on the X-ray Console) with no alumi-
num sheet on the compression paddle, and read the dose value on the dosimeter.
8. Press
Set Up
once on X-ray Console, select
Meas.D
,
enter the dose value E
0
in mGy (see Notice
above) and
press
Valid
.
9. Press
Set Up
twice, and select
0.2
.
Configuration
X-Ray Console Path
Mo/Mo
SET UP/GENE/INSTAL/GENE/DOSE /LF/MOMO/CALIB/0/CALIB
Mo/Rh
SET UP/GENE/INSTAL/GENE/DOSE /LF/MORH/CALIB/0/CALIB
Rh/Rh
SET UP/GENE/INSTAL/GENE/DOSE /LF/RHRH/CALIB/0/CALIB