Fluke Biomedical 35080M - Manual (Page 54)

Appendix
Linear Measurement
A
A-3
LINEAR MEASUREMENT PROCEDURE
Part A
1. With the generator settings used for K-edge measurement in Part C make an exposure.
2. Record the voltage in box E (Figure A-2), then multiply the voltage in box E by 100 and record as
kVp in box F.
Part B
1. Subtract the kVp in box F from the kVp in box D (Figure A-2). (This will be the CORRECTION
VALUE applied to all kVp measurements made with the Linear Mammo Filter Pack, 37351C.)
2. Insert this value in all spaces in the column labeled ‘‘CORRECTION VALUE.’’
This value may be either positive or negative.
Part C
1. Measure other kVp values as desired.
2. Enter the voltage in the ‘‘LINEAR VOLTAGE’’ column on the data sheet, multiply by 100.
3. Enter the value in the ‘‘LINEAR kVp’’ column.
4. Apply the CORRECTION VALUE to all kVp's by either adding to or subtracting from the ‘‘LINEAR
kVp’’ column, and record the results in the ‘‘CORRECTED kVp’’ column. (This column now has the
true kVp value for all kVp's measured.)
Part D
If the position of the Model 35080M kVp Divider changes during the Linear kVp measurement, you must
repeat the measurement starting with Part C: some of the correction value is positional dependent.
Set
kVp
K-edge
Voltage
True
kVp
Linear
Voltage
Linear
kVp
Correction
Value
Corrected
kVp
22 ⎯⎯⎯ ⎯⎯⎯ 0.213 21.3 +0.8 22.1
23
⎯⎯⎯ ⎯⎯⎯
0.221 22.1 +0.8 22.9
24
⎯⎯⎯ ⎯⎯⎯
0.230 23.0 +0.8 23.8
25
(A)
3.10
⎯⎯⎯
0.237 23.7 +0.8 24.5
26
(B)
3.10
⎯⎯⎯
0.249 24.9 +0.8 25.7
27 ⎯⎯⎯ ⎯⎯⎯ 0.255 25.5 +0.8 26.3
28
⎯⎯⎯ ⎯⎯⎯
0.267 26.7 +0.8 27.5
29
()
3.26
(D)
28.6
(E)
0.278
(F)
27.8 +0.8 28.6
30
⎯⎯⎯ ⎯⎯⎯
0.287 28.7 +0.8 29.5
31 ⎯⎯⎯ ⎯⎯⎯ 0.299 29.9 +0.8 30.7
32 ⎯⎯⎯ ⎯⎯⎯ 0.308 30.8 +0.8 31.6
33
⎯⎯⎯ ⎯⎯⎯
0.319 31.9 +0.8 32.7
34
⎯⎯⎯ ⎯⎯⎯
0.33 33.0 +0.8 33.8
35
⎯⎯⎯ ⎯⎯⎯
0.342 34.2 +0.8 35.0
36 ⎯⎯⎯ ⎯⎯⎯ 0.351 35.1 +0.8 35.9
NOTE
Figure A-1. The Model 35080M Mammograhic Worksheet (Example)