GE Healthcare
Senographe DS
Revision 1
Service Information and Procedures Class A 2385072-16-8EN
Job Card CAL A046 - Half-Value Layer Measurement
Page no. 1707
Chapter 9
JC-CAL-A-046.fm
8-2
Information:
The Senographe automatically computes the HVL by interpolation using the following formula:
(
the units are mm of Al)
Where E
0
, E
0.2
, E
0.5
, are dose values measured behind 0, 0.2 mm and 0.5 mm aluminum respectively.
The Senographe calculates Tube Yield as E
0
/ mAs (unit: mGy/mAs) for this technique.
9
COMPLETION
If you are handing the machine back to the user at this point, switch the Senographe off, then on again.
)
Ε
/
Ε
(
)
/
(2
∗
0.2
−
)
/
=
0.5
0.2
ln
E
E
ln
E
E
ln(2
*
0.5
HVL
0
0.5
0
0.2
