Coefficients Of Calibration Curves - Agilent Technologies 7500 ICP-MS Operator's Manual

Agilent 7500 ICP-MS ChemStation Operator's Manual
Appendix

Coefficients of Calibration Curves

Coefficients are calculated as follows.
where
n : number of points
x : numbered value of x
i
y : measured value of y
i
w : weight of each point ( w
i
1 y = ax
∑
x y w
i i i
=
i
a -------------------- -
∑
2
x w
i i
i
2 y = ax + b
⎛
∑
⎜
n x y w
i i i
⎝
i
=
a -------------------------------------------------------------------------------- -
⎛
∑
⎜
n x
⎝
i
∑
∑
y w
i i
= –
i
---------------- -
b ---------------- - a
n
=1.0 in the case of unweighted regressions)
i
⎞ ⎛ ⎞ ⎛
∑ ∑
⎟ ⎜ ⎟ ⎜
–
x w y
i i i
⎠ ⎝ ⎠ ⎝
i i
⎞ ⎛ ⎞
2
∑
2
⎟ ⎜ ⎟
–
w x w
i i i i
⎠ ⎝ ⎠
i
x w
i i
i
n
⎞
⎟
w
i
⎠
A-15