Metrohm viva 1.0 Manual - Manual (Page 583)

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5 Method
viva 1.0
￭￭￭￭￭￭￭￭ 571
Linear interpola-
tion y =
k(0)
+
k(1)
⋅ x
≥2
At least three points are required for being able to generate a non-linear
or quadratic calibration. A suitable curve fit (quadratic or non-linear) must
be placed on the points so that the calibration curve is available in the
curve display and/or so that the calibration curve can be calculated. Fig. 1
shows the first three points of the calibration, which lie upon a line. This
curve can not be evaluated with a non-linear or quadratic curve type. For
the purposes of evaluation, the calibration curve must intersect the line
with the evaluation ratio and may not lie parallel to it.
Figure 1 Fig.: 1
An additional, fourth point is required for the calibration so that the non-
linear or quadratic function is laid on the points and so that extrapolation
can be carried out to the intersection point with the evaluation ratio (see
Figure 2, page 571).
Figure 2 Fig.: 2