GE Senographe DS Manual page 684

GE Healthcare
Revision 1
Job Card ELE A028 - Collimation Checks
7-2 Measurements
7-2-1 X-ray Field Passing All Four Edges
From the RAW digital image on the AWS determine, whether each of the four edges of the X-ray field
are outside of the edge of the image receptor. That is, you should not be able to see any of the four
edges of the X-ray field in the digital image.
• If you can see any of the four edges of the X-ray field in the digital image, there is a problem with the
Collimator blade alignment. In this case, you must re-calibrate the Collimator. Once you have re-cali-
brated the Collimator you must take new exposures before you continue with the measurements
described in section 7-2-2
• If you cannot see any of the four edges of the X-ray field in the digital image, the Collimator blades
are aligned correctly. You can continue with the measurements described in
tion 7-2-3.
7-2-2 XR-M Film Measurements
From the film and AWS (Acquisition Workstation) RAW digital image, you must make various measure-
ments as described below. Use the Segment tool on the AWS for measurements on the image receptor.
Measurements both from the film and the AWS must be scaled to the image receptor plane.
You must follow the measurements and calculations described below for each edge of the field (each
XR-M film strip A, B, C and D), and complete the following tables.
In the tables below, items in bold italics are measured/determined and items in bold are calculated.
Mo/Mo
Left edge (Film A)
Anterior edge (Film B)
CW edge (Film C)
Right edge (Film D)
Rh/Rh
Left edge (Film A)
Anterior edge (Film B)
CW edge (Film C)
Right edge (Film D)
Chapter 7
Service Information and Procedures Class A 2385072-16-8EN
and section 7-2-3.
Step 1 Step 2
Y D
Z = D -
f f
Step 1 Step 2
Y D
Z = D -
f f
Page no. 684
Step 3
Y Global Scaling Factor (S) =
f
1.063 x d (in mm) / 10
Step 3
Y Global Scaling Factor (S) =
f
1.063 x d (in mm) / 10
Senographe DS
section 7-2-2 and sec-
Step 4
Z
i
(S x Z )
f
Step 4
Z
i
(S x Z )
f
JC-ELE-A-028.fm