CPI Indico 100 Series Service And Installation Manual page 220

Reproducibility, Linearity, & HVL Testing
3.0 REPRODUCIBILITY (Cont)
4. Calculate and record the average dose mR.
5. Calculate the difference mR - mR for each exposure.
6. Square each difference from the previous step.
7. Calculate the sum of the differences squared.
8. Calculate the standard deviation (S) by using the formula.
9. Calculate reproducibility by dividing S by mR.
10. Table 5 shows example reproducibility calculations.
11. If linearity is to be measured, it is suggested that dose measurements be taken at this time for
entry into tables 6 and 7. Refer to 4.0 LINEARITY for details.
IN TABLES 1 TO 4, 3 POINT MEANS THAT FOR GENERATORS WHERE KV, MA, AND TIME
SELECTION IS AVAILABLE, THE KV, MA AND MS VALUES SHOWN SHOULD BE USED. FOR
GENERATORS WHERE 2 POINT OPERATION ONLY IS AVAILABLE, THE KV AND MAS VALUES
SHOWN SHOULD BE USED.
3 point = Minimum kV, maximum mA, 100 ms.
2 point = Minimum kV, maximum mAs.
EXP No.
1
2
3
4
5
Calculate standard deviation (S) using formula at beginning of this section:
Calculate reproducibility =
Page 4
DOSE (mR)
Calculate each of the differences
ie: DIFF
mR =
1
Repeat for each remaining mR
________
value.
S = _________ (not to exceed 0.045)
mR
Table 1: Reproducibility
Rev. A X-Ray Generator Service Manual Supplement
DIFFERENCE
= mR - mR.
1
CPI Canada Inc
mAs = __________
DIFFERENCE
Square each difference. Then
calculate the sum of the difference
2
Sum of difference = _________
S = __________
2
2
.
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