Canon CXDI-40G COMPACT, Руководство по обслуживанию

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2. Installation
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10.3 Adjustment
It is advisable to leave the photo timer adjustments in the hands of the individual representing the
manufacturer of the X-ray generators.
Basically, it is essential that the manufacturer’s representatives perform these adjustments at the same
time as the film screen and/or screen system adjustments.
(1) Have ready the 5cm, 10cm, and 20cm photo timer adjustment acrylics sheets, proceed to X-ray at
70k V, 100kV and 120kV, respectively, and adjust the photo timer so that the Rex value is 650. (At
this step, it is mainly the sensitivity difference that is based on the radiation quality of the photo timer
which is adjusted.)
(2) Adjust the radiation dosage gradually using the option buttons (such as the H.S button, L.S button,
“+” (plus) and “-“ (minus) button) on the X-ray generator, and decide on the final dosage.
For instance, the L.S button is for providing about 1.5 times the default dosage.
If, in overall terms, the sensitivity has shifted slightly or it differs slightly from one body part to
another, use the H.S, L.S, “+” and “-“ buttons on the X-ray generator to adjust the sensitivity as
required.
Reference: If the Rex value is set as in the list when the acrylic sheet was X-rayed under the
conditions set by the above “Adjustment button”, this value will be in the order of 300 to
350 when the “Chest front” button is used and the chest front of a person is X-rayed under
the following conditions.
Automated ROI#3(CHEST PA)/ with back ground
CURVE SHAPE: CHEST
BRIGHTNESS: 16
CONTRAST: 10
With auto ROI, all the
areas are turned off .