CPI CMP 200 Series Service Manual page 225

CPI Canada Inc.
3D.6.0 AEC CALIBRATION (WALL BUCKY) Cont
NOTE: SINCE MOST WALL BUCKYS ARE USED AT 40 AND 72 IN. (100 AND 180 CM) SID, THE GRID MUST BE CHOSEN WITH CARE
WITH RESPECT TO CUT-OFF.
A TYPICAL GRID WILL HAVE AN 8:1 RATIO, WITH 85 LINE PAIR / INCH OR 10:1 RATIO WITH 150 LINE PAIR / INCH
(STATIONARY).
TYPICALLY, 400 SPEED FILM SCREEN WILL BE USED WITH 90 SECOND PROCESSING.
Grid Absorption
The following information may aid in selecting a grid and / or estimating mAs if required: The percentages listed are approximate.
A 10:1 ratio 60 in. (150 cm) focused grid will exhibit the following absorption when measured 5 in. (13 cm)
from center:
At 72 in. (180 cm) absorption = 18%
At 40 in. (100 cm) absorption = 40%
A 12:1 ratio 60 in. (150 cm) focused grid will exhibit the following absorption when measured 5 in. (13 cm)
from center:
At 72 in. (180 cm) absorption = 20%
At 40 in. (100 cm) absorption = 50%
A 10:1 ratio 72 in. (180 cm) focused grid will exhibit the following absorption when measured 5 in. (13 cm)
from center:
At 40 in. (100 cm) absorption = 65%
A 12:1 ratio 72 in. (180 cm) focused grid will exhibit the following absorption when measured 5 in. (13 cm)
from center:
At 40 in. (100 cm) absorption = 75%
A 10:1 ratio 40 in. (100 cm) focused grid will exhibit the following absorption when measured 5 in. (13 cm)
from center:
At 72 in. (180 cm) absorption = 65%
A 12:1 ratio 40 in. (100 cm) focused grid will exhibit the following absorption when measured 5 in. (13 cm)
from center:
At 72 in. (180 cm) absorption = 75%
Use and disclosure is subject to the restrictions on the title page of this CPI document.
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CMP 200 Service Manual Ch # 901476-05 Rev. A
3D
AEC Calibration
Page 3D-32