Fluke Biomedical 199XRAY - Manual (Page 11)

Using the X-RAY kVp Function
Selecting a Filter Pack
2
2-3
Cadmium K-edge Mammo Filter Pack Calibration
Overview
During Cadmium K-edge Mammo Filter Pack calibration,
screen instructions will guide you through the calibration
steps. This section provides an explanation of the
calibration steps.
Read the mammographic filter pack sections of the Model
35080/A/B/M kVp Divider Instruction Manual to become
familiar with the specifications, theory of operation, and
application of corrections for these filter packs.
K-edge Measurement Setup:
Install the Cadmium K-edge Filter Pack in the kVp Divider.
Place the kVp divider in the x-ray beam on the
compression paddle or other suitable support with the long
axis of the kVp divider perpendicular to the axis of the x-
ray tube. Raise the kVp divider as close as possible to the
x-ray tube. The x-ray beam should cover the entire filter
pack. Select the k-Edge Mammo filter pack from the filter
pack menu.
25 kVp Measurement Procedure:
Set the x-ray generator for 25 kVp, 100 mA, 80 ms. If not
available, use a mAs setting that provides an exposure of
80 ms (+/- 10 ms). Select the molybdenum (Mo) filter on
the generator. Make the first baseline measurement.
26 kVp Measurement Procedure:
Repeat the baseline measurement at a slightly higher kV
setting that should still be below the k-edge (26.7 kV). Set
the generator for 26 kVp,100 mA, 80 ms. If not available,
use a mAs setting that provides an exposure of 80 ms (+/-
10 ms).
If the voltage difference between the first and second
baseline measurements is within the limits (+/- 20mV), this
is the baseline voltage. If the voltage difference is outside
the limits, repeat the above measurements at 24 kVp and
25 kVp respectively.
29kVp Measurement Procedure:
Set the generator for 29 kVp,100 mA, 80 ms. If not
available, use a mAs setting that provides an exposure of
80 ms (+/- 10 ms). Make the k-edge kV reference
measurement.