Metrohm 746 VA Trace Analyzer User Manual

Page 478

6.7 Baseline calculation

746 VA Trace Analyzer / 747 VA Stand

6-15

If two points with identical slope are found, the two points of tangency are

connected with each other to give the linear baseline. If no common slope is

found, the linear baseline is drawn directly through the two base points.
Instead of being determined

automatically, the two base

points

dU.front

and

dU.rear

can also be entered manually by

numeric entry.

In contrast, the

two slopes

S.front

and

S.rear

are always calculated automati-

cally, a numeric entry here is ig-

nored.

linear, f.double

linear, r.double

•

Type = polynom, Scope = whole

In the baseline of type

polynom

, the curvature of the peak baseline is appro-

ximated by a polynomial curve. With the previously determined peak base

points

dU.front

and

dU.rear

as a basis, the two associated slopes

S.front

and

S.rear

are used to calculate the curved baseline.

The two base points

dU.front

and

dU.rear

well as the two slopes

S.front

and

S.rear

can

also be entered manually

instead of being deter-

mined automatically.

polynom, whole

dU.front dU.rear

•

Type = polynom, Scope = f.double/r.double

This type of baseline is used for the evaluation of overlapping peaks; for the

peak the type

polynom, f.double

must be used and for the 2

peak the

type

polynom

r.double

. The baseline is calculated in exactly the same man-

ner as for

polynom

whole

. With the previously determined peak base points

dU.front

for the 1

peak and

dU.rear

for the 2

peak as a basis, the two

associated slopes

S.front

and

S.rear

are used to calculate the curved

baseline.
The two base points

dU.front

and

dU.rear

as well as the two

slopes

S.front

and

S.rear

can also be entered manually

instead of being determined

automatically.

polynom, f.double

polynom, r.double

•

Type = expon., Scope = whole

With the baseline of type

expon.

, the curvature of the peak baseline is ap-

proximated by an exponential curve. With the previously determined peak

base points

dU.front

and

dU.rear

as a basis, the two associated slopes

S.front

and

S.rear

are used to calculate the exponential baseline.

Subtracted

curve

Base point

(rear)

Base point

(front)