AGFA Drystar 5500, Справочное руководство

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148
2900H EN 20071108 Advanced operation (Key-operator mode)
D
RYSTAR
5500/5503 R
EFERENCE MANUAL
Verifying Acceptable Spatial Resolution, Artifact Levels and Low Contrast
Visibility for general radiography applications (DT 2 B and DT 2 C)
To verify acceptable spatial resolution, artifact levels and low contrast
visibility, proceed as follows:
1
Print the QC general radiography test image or use the previously printed QC
general radiography test image used to establish the daily operating density
levels.
2
Visually check the QC general radiography test image for artifacts: no
significant disturbing artifacts should be visible.
3
Check the spatial resolution in each of the three ovals. Within each oval there
are three groups, each having five dots. All five dots of each group must be
visible with a magnifying glass. The smallest cluster of 5 dots is only visible if
the viewing conditions are good.
4
Check the Low Contrast Visibility at both the high (100 / 95%) and low end
(0 / 5%) of the density scale. You should be able to see the circle in the square
(refer to item 1 on the
‘QC general radiography test image’ on page 146 ) and the
upper circle (refer to item 2 on the ‘QC general radiography test image’ on
page 146 ).
5
Record these values at the top of Chart 3 (‘Drystar 5500/5503 Artifacts and
Spatial Resolution Control Chart’). Refer to
‘Charts for general radiography QC’
on page 242 .
6
These charts will be used for the weekly quality test. For more information,
refer to
‘Performing the Weekly QC tests for general radiography applications
(DT 2 B and DT 2 C)’ on page 151 .
Good viewing conditions are important for the correct interpretation of
both diagnostic and test images. Make sure that the light box intensity
(luminance) is between 2000 and 4000 cd/m² (4500 and 6500 °K) for
general radiography. Use a magnifying glass and use shutters to collimate.
Make sure the ambient light is low.
In case of significant artifacts or insufficient spatial resolution, the cause
must be found and the problem solved before any further clinical films can
be printed.
Refer to ‘Maintaining image quality and resolving Image quality problems’ on
page 220 and ‘Preventive maintenance schedule’ on page 186 , or call your
local Agfa service organization.