Metrohm 746 VA Trace Analyzer User Manual

Page 411

5.7 Program instructions

746 VA Trace Analyzer / 747 VA Stand

5-260

Comments

•

The

PSAMODE

measurement mode can be used only with the

electrode types

RDE

and

HMDE

and must be employed together with

the

PSWEEP

instruction.

•

The electrode type

RDE

HMDE

must be entered before the

PSAMODE

measurement mode.

•

The measurement time

t.meas

for the measurement of the voltage

drop is divided into 11 windows of different size in which 64 meas-
ured values are recorded each time (resulting in a total of 704 meas-
ured values per segment). The first measurement window has a size
of 2.944 ms, each subsequent window is twice as large as the pre-
ceding window.

•

With mercury film electrodes based on the RDE, it is advisable to
deposit the substances with stirring on the electrode. As in the

PSWEEP

instruction, only an enrichment without stirring is possible (no

stirring is allowed during measurement), the

MEAS

instruction must be

inserted. The enrichment time with stirring is defined by its line time,
in general

U.meas = U.start

is selected for the measurement volt-

age.

Example

see

PSWEEP

see also

PSWEEP, MEAS, RDE, HMDE