Metrohm 746 VA Trace Analyzer User Manual

Page 282

5.6.3 SUBSTANCES

746 VA Trace Analyzer / 747 VA Stand

5-131

Parameter

Range; Default value / Meaning

Method

display only

Method name

Name of the method loaded in the working memory.

Subst# -
Segment#

8 characters;

Substance name and segment name

Name of the displayed substance and the associated segment. To
change the substance name, the softkey

must be

pressed.
The segment name is shown only if the substance has first been
linked to a segment using the softkey

Recognition

display only

Substance recognition

Title for those parameters which concern recognition of the sub-
stance.

U.verify

-3000...3000 mV;

Characteristic voltage

Verification voltage for the assignment of a peak or a wave to a
substance. The voltage

aU.peak

aU/2

estimated in a first ap-

proximation must be within the range

U.verify

±± U.tol

for the

substance to be recognized (see adjacent diagram and section 6.6).
If the characteristic voltage is not known before the first measurement,
this field (or with several substances, these fields) can be left blank.
The first peak or wave found in the segment is then assigned to the
first substance allocated to this segment, the second to the second,
etc.
Following the first measurement, the voltages

U.peak

U/2

of the

peaks/waves found in the segment are shown on the softkeys when
the

U.verify

field is edited and can hence be adopted directly:

XXXXXXXX

--------

The displayed voltage

XXXXXXXX

is copied to the

U.verify

field.

U.tol (+/-)

1...150 mV; 30 mV

Tolerance for characteristic voltage

Tolerance of the verification voltage for the assignment of a peak or
wave to a substance. The voltage

aU.peak

aU/2

estimated in a

first approximation must be within the range

U.verify

±± U.tol

for the

substance to be recognized (see adjacent diagram and section 6.6).
With peaks that are close together, it is advisable to choose toler-
ances which are not too large, otherwise an unambiguous assignment
to the substances can no longer be assured owing to the overlapping
ranges.

U.width min

1...(U.width max) mV; 10 mV

Minimum peak width

Minimum peak width for the assignment of a peak or a wave to a
substance. The peak width

aU.width

estimated in a first approxima-

tion must be larger than

U.width min

for the substance to be recog-

nized (see adjacent diagram and section 6.6).