HF Series Generators
Calibration
CA-1036R2
61
8. Make a Fluoro exposure at 70 kV and measure the radiation. Optimum
radiation is obtained by modifying the Fluoro kV or the Copper thickness
in the Collimator Filter Holder. First modify the Fluoro kV, if it is more than
80 kV or less than 60 kV modify the Copper thickness in 0.1 mm (or
0.2 mm). Note the value of Fluoro KV and Copper thickness used to
obtain the optimum radiation.
Radiation increases when kV is increased or Copper thickness is
reduced.
9. Perform the adjustment for the window test. This window defines the
area of the image where the brightness will be captured for the ABC.
a. Calculate the image area πr
2
(clear circle on the monitor). (r=circle
radius).
b. Calculate the 25% of the image area ( πr
2
/4).
c. Calculate the sides of the window: l = πr
2
∕4
(I= side of square).
d. Mark the calculated area on the monitor (square).
e. Position jumper JP18 of RF Adaptation Board in “A”. A window will
be displayed on the monitor.
f. Adjust in the RF Adaptation Board the following potentiometers to
move the window under the frame marked on the monitor in
step--d:
-- R1 potentiometer (vertical position)
-- R2 potentiometer (vertical width)
-- R3 potentiometer (horizontal position)
-- R4 potentiometer (horizontal width)
g. Once the window is configured, place JP18 in “B” again at RF
Adaptation Board.
10. Select the 70 kV (or the kV obtained in step-8.) and Non-ABC mode.
11. Adjust the gain at R 27 on the R F Adaptation Board to make the “ABC
OUT” signal equal to +6 VDC. Measure “ABC OUT”inTP7ofRF
Adaptation Board o r in TP3 (”ABC IN”) of the AEC Control Board.
Note .
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