10 Calculation Methods
10-8
2
)(
)()(
∑
∑
=
=
−
−⋅−
=
M
Ii
i
i
M
Ii
i
TT
AATT
R
Where, I - high limit of linear range, M - low limit of linear range, A
i
- absorbance at i,
- average absorbance between I and M, Ti - time at I,
- average time between I
and M
Double-wavelength (for both single-reagent and double-reagent)
The calculation method is similar to that for single-wavelength reaction, except for every
measurement period, the absorbance is the difference between primary wavelength
absorbance and secondary wavelength absorbance.
10.2.3 Calculating Calibration Parameters
The system provides two calibration methods: linear calibration and nonlinear calibration.
Linear calibration includes one-point linear calibration, two-point linear calibration and
multi-point linear calibration. They are mainly used for tests determined by colorimetry.
Nonlinear calibration includes Logit-Log 4P, Logit-Log 5P, Exponential 5P, Polynomial 5P,
Parabola and Spline. They are mainly used for tests determined by turbidity.
In this section,
- calibrator response
C
- calibrator concentration (activity)
,
0
,
, b ,
- calibration parameters
10.2.3.1 Calculating Linear Calibration Parameters
One-point linear calibration
Calibration formula:
aCR
This calibration method adopts only one calibration parameter
,
R
.
This calibration method requires only one calibrator.
Two-point linear calibration
Calibration formula:
baCR
.
This calibration method adopts two calibration parameters:
and
b
, where,
12
12
CC
RR
a
−
=
,
1
12
12
1
C
CC
RR
Rb )(
−
−=
.
This calibration method requires two calibrators.
C
1
and
C
2
are respectively the
concentrations of calibrator 1 and calibrator 2.
1
and
2
are respectively the
responses of calibrator 1 and calibrator 2.