6-
Spline
Spline defines several calculation sections based on the responses of calibration
concentrations. Each section differs in specific parameters. Therefore, the section to
which the current response belongs should be confirmed before Spline calculation.
The parameters of relevant section shall be used to obtain a positive real root with
the dichotomy method.
6.4 QC Rule
6.4.1 Westgard Multi-rule
Westgard multi-rule is shown below.
Symbol Explanation QC
Conclusion
1
2S
One control value
exceeds ±2 standard
deviations.
Warning
1
3S
One control value
exceeds ±3 standard
deviations.
Out-of-control
(random
error,
systematic
error)
2
2S
Two consecutive
control values for one
level exceed ±2
standard deviations.
Out-of-control
(systematic
error)
R
4S
The difference
between two
consecutive control
values exceeds 4
standard deviations.
Out-of-control
(random
error)
4
1S
Four consecutive
control values for one
level exceed ±1
standard deviation.
Out-of-control
(systematic
error)
10
X
Ten consecutive
control values for one
level lie on one side
of the mean.
Out-of-control
(systematic
error)
Westgard multi-rule QC conclusion flow for single control is shown in Figure 6-3.