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Protos 3400(X)
SW 3400-009: Concentration Determination
Select menu: Parameter setting/System control/Module COND/Concentration
Default settings and selection range
Concentration determination
The substance concentration in percent by weight (% by wt) is determined
for H
2
SO
4
, HNO
3
, HCl, NaOH, NaCl from the measured conductivity and
temperature values.
Conditions for concentration determination
Below you find tables with the concentration ranges of the preset substances.
These tables show the conductivity of the substances versus substance
concentration and process temperature.
The following conditions must be met for a reliable concentration
determination:
• For calculation of concentration, the medium to be measured must be
a purely binary mixture (e.g. water-hydrochloric acid). Presence of other
dissolved substances (e.g. salts) leads to incorrect concentration values.
• In the region of small slopes (e.g. at the range limits) small conductivity
changes can correspond to great concentration changes.
This may lead to an unsteady display of the concentration value.
• As the concentration value is calculated from the measured conductivity and
temperature values, accurate temperature measurement is very important.
Therefore, you should make sure that sensor and process medium are in
thermal equilibrium.
Messages
You can define limits for warning and failure messages for the concentration
value:
Select menu: Parameter setting/System control/Module COND/Messages
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