Metrohm 743 Rancimat - Manual (Page 174)

6.1 Problems ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
166 ￭￭￭￭￭￭￭￭ 743 Rancimat
Problem Cause Remedy
The reaction vessels used
are scratched on the
inside. Only use new, unused reaction vessels.
The reaction vessel cover
(5-
8 ) is not mounted cor-
rectly or is too loose.
￭ If the reaction vessel cover is oblique or not
completely mounted, press down as far as
the limit stop.
￭ If the reaction vessel cover is loose on the
reaction vessel despite correct assembly,
the cover has to be replaced.
The connection to the
measuring vessel is not
mounted correctly. Ensure that no air can escape through leaks
when transferring from the reaction vessel to
the measuring vessel.
The temperature in differ-
ent channels of a heating
block differs, as there are
burn marks at one or more
places in the opening of
the heating block. Check temperature in the different positions
(see Chapter 4.8.4.1, page 145). If necessary,
carefully remove the impurities from the cold
heating block.
The temperature in differ-
ent heating blocks differs. Determine the temperature correction Delta T
for each block separately (see Chapter 4.4.2,
page 50).
The sample is not homoge-
nous. Homogenize sample.
The stability times
are not reproducible
for multiple determi-
nations. The cell constant was not
determined or does not
correspond to the value
entered. ￭ Determine cell constant (see Chapter 4.4.1,
page 48).
￭ Ensure that the measuring cell is always
used in the same channel, so that the cell
constant determined once also corre-
sponds to the measuring cell.
￭ Ensure that the measuring cell is not conta-
minated. If necessary, clean (see Chapter
4.6.5, page 83).
The conductivity measuring
cell is contaminated. Check measuring cell (see Chapter 4.8.4.2,
page 150) and, if necessary, clean.
See also: The induction
times are not reproducible
for multiple determina-
tions.