400 / 1084
Total systematic and random
uncertainties
•
Why “quadratic sum”?
For a simple criterion such as probability level of minimum dose,
random and systematic uncertainties could be added linearly.
For the separate systematic and random uncertainties a
quadratic
sum
is required:
S = S + S + S
M
=
M
sys
+
M
r
It emphasizes the large uncertainties
!!! (see example)
a
2
b
2
c
2
S =
10
2
+
3
2
+
3
2
=
10.9
The PTV 2017 - D. Verellen