Fluke Biomedical TNT 12000 - Manual (Page 101)

Model 96020C Ion Chamber
Calibration and Verification
A
A-7
Typical Correction Factors - Unattenuated Beam
Normalized to DV70
First HVL (mm A1)
Colrrection Factor
1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
1.05
1.04
1.03
1.02
1.01
1
0.99
0.98
0.97
0.96
0.95
40
30
50
70
120
150
90
100
fct38.eps
Figure A-6. Energy Correction Factors for Model 96020C in Unattenuated Beam Normalized to DV70
All 96020C ion chambers must have an actual correction factor within ± 1.5 % of the
value shown in the curves at any point. Users receiving the standard calibration must
request a calibration factor at either L100 or DV70 to use the correction factors in these
curves.
The numerical value shown beside each point is the kVp value of that point in the DV
series of beam qualities. Users making measurements in an unattenuated beam may use
these values to easily obtain the appropriate correction factor. For a more precise
correction factor value, the user may calculate the actual first HVL and locate the proper
correction value on the curve.
Note
Introduction of material, other than free air, behind the Ion Chamber will
cause its response to change due to backscatter.