Averaging Repetition Files - Agilent Technologies 7500 ICP-MS Operator's Manual

Agilent 7500 ICP-MS ChemStation Operator's Manual
Appendix

Averaging Repetition Files

When the repetition data files are averaged to create an average results file, the
following formulas are used:
∑
n x
i i
=
i
x --------------- -
avg
∑
n
i
i
∑ ∑
2
n x
i
i i
=
s ---------------------------------------------- -
avg
⎛
∑ ∑
⎜
n
i
⎝
i i
where
∑ ∑
=
x n x
i i
i i
(
–
n n
∑ ∑
2
i i
=
x ------------------------------------------------- -
i i
x : average count of the averaged results file
avg
s : standard deviation of the averaged results file
avg
n : repetition number of the individual repetition file
i
x : average count of the individual repetition file
i
: standard deviation of the individual repetition file
s
i
A-28
⎛ ⎞
2
∑
⎜ ⎟
–
x
⎝ ⎠
i
⎞
⎟
–
n 1
i
⎠
)s 2 ( ) 2
+
1 n x
i i i
n
i