Eppendorf BioSpectrometer basic - Manual (Page 91)

91
Evaluation procedure
Eppendorf BioSpectrometer ® basic
English (EN)
12.2 Evaluation with factor or standard
C = calculated concentration.
A = absorbance.
F = factor.
The factor is programmed in the parameter list and can be modified. It always relates to an optical path
length of the cuvette of 10 mm. If you change the
Cuvette parameter the device will take the modification
into account when calculating the results. Therefore you do not need to change the factor for the
evaluation.
If, on the other hand, you modify the concentration unit, you have to ensure that the factor is adjusted for
the selected unit.
The factor is either entered directly as a parameter during the "Factor" evaluation procedure or calculated
during the "Standard" evaluation procedure (evaluation with a standard concentration):
F = calculated factor
C
S
= concentration of the standard (enter as parameter).
A
S
= measured absorbance of the standard.
If multiple measurement (2 or 3 replicates) has been programmed for the standard, the average value is
calculated from the measured absorbance values and inserted as
A
S
.
12.3 Evaluation with standard curve/line
If evaluations are made with more than one standard, the following evaluation procedures for the standard
curve/line can be selected with the [Curve fit] in the
measure standards/new method step:
For the regression procedure, one can select that the regression line (regression curve) goes through the
zero point.
Evaluation procedure Description Minimum required number
of standard points
Linear interpolation Linear point-to-point connection in the
absorbance concentration graph of the standard
evaluation. 2 standards minimum.
Linear regression Polynome regression for first degree polynomial. 3 standards minimum.
Quadratical regression Polynome regression for second degree
polynomial. 4 standards minimum.
Cubical regression Polynome regression for third degree polynomial. 5 standards minimum.
Spline interpolation Interpolation via natural cubic splines. 3 standards minimum.
F A C
u
S
S
A
C
F