Fluke Biomedical TNT 12000 - Manual (Page 111)

Model 96035B Ion Chamber
Calibration and Verification
B
B-9
All 96035B ion chambers must have an actual correction factor within ± 1.5 % of the
value shown in the curves at any point.
The actual points plotted in the graphs below correspond to the points in the MV and MH
series of beam qualities. Users making measurements at a beam quality similar to one of
the PTB mammographic beams may easily obtain the appropriate correction factor by
assuming the HVL of the most equivalent PTB beam. 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.