56
2801E EN 20050215
Advanced operation (key-operator mode)
D
RYSTAR
4500 U
SER
MANUAL
Verifying Acceptable Spatial Resolution, Artifact Levels and Low
Contrast Visibility
To verify acceptable spatial resolution, artifact levels and low contrast
visibility, proceed as follows:
1
Print the QC Test image or use the previously printed QC Test image used to
establish the daily operating density levels.
2
Visually check the QC 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
on page
) and the upper circle (refer to
item 2 on the
on page
5
Record these values at the top of the Drystar 4500 Chart 3 (Drystar 4500
Artifacts and Spatial Resolution Control Chart). Refer to
on page
6
These charts will be used for the weekly quality test. For more information,
refer to
‘Performing the Weekly QC tests’
on page
.
Good viewing conditions are important for the correct interpretation of
both diagnostic and test images. Make sure that the lightbox intensity
(luminance) is between 2000 and 4000 cd/m² (4500 and 6500 °K). 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.
‘Maintaining image quality and resolving image quality problems’
page
of the Drystar 4500 Reference manual and ’
on page
, or call your local Agfa service
organization.
2801 E EN UM Drystar 4500.fm Page 56 Monday, February 21, 2005 2:32 PM