KaVo 3D eXam, Operator'S Manual

Page: 107 / 170

k990400 September 19, 2007
Calibration and Quality Assurance
10-17
Noise Level Test
14. Zoom the Axial image (upper left). To zoom, start at the lower
right corner of the image and drag the cursor across the image.
15. Right click the image and select HU Statistics from the menu.
Use the Region Tool to define a ROI (Region of Interest) in the
center of Water and also the Air (outside area of the water bowl),
as shown above.
HU Area (box size) should be approximately:
1000.0 mm
2
inside the Water Phantom area
400.0 mm
2
outside the Water Phantom area (AIR)
16. Note and record the values of both the Water and Air areas. See
chart below.
NOTE:
Do not close image. This image is also used for the
Uniformity Test (next procedure).
17. If the Standard Deviation ( SD ) Measured Value exceeds 100 ,
call Service.
Measured Values Water Air
Mean
Expected Values
0 +50 -1000 +50
SD