Endress+Hauser Topclean S CPC30, Operating Instructions Manual

Page: 62 / 178

6 Commissioning Topclean S
62 Hauser
6.6.6 Set up 1 – Temperature
The pH value requires temperature compensation for two reasons:
1. Temperature effect of the electrode:
The electrode slope is dependent on the temperature. Therefore this effect must be
compensated for temperature changes (
temperature compensation , see below).
2. Temperature effect of the medium:
The medium pH value is also temperature dependent. For high-accuracy measurements, the
pH value related to temperature can be entered in table form (
medium temperature
compensation , see below).
Temperature compensation
ATC: Automatic temperature compensation: The medium temperature is measured with a
temperature sensor. This temperature is used via the temperature input in the Mycom S CPM153
to adjust the electrode slope to the medium temperature.
MTC: Manual temperature compensation: This is advisable in processes which run at a constant
temperature. Here, you enter the temperature value manually, which is used to adjust the slope of
the electrode to the medium temperature.
MTC+Temp.: The pH value is corrected with the manually entered temperature (see MTC). The
display, however, shows the value that the temperature sensor measures in the medium.
Medium temperature compensation
Tables for Medium 1...3:
For medium temperature compensation, tables can be created in the CPM153 for three different
media. Before starting the process, the most suitable table for the active medium can be selected.
Procedure:
• Take a sample from the process. The pH value should be as near as possible to the reference value
of the process.
• In the laboratory, heat the sample to at least the process temperature.
• During cooling, record the value pairs for pH and temperature at those temperatures at which you
later wish to take measurements (e.g. process temperature and ambient temperature in the
laboratory).
• Enter these recorded value pairs in the table (field "Value pair entry"). As a reference temperature
(Field "Reference temperature entry") select the temperature, at which the reference value of the
process is defined (e.g. ambient temperature in the laboratory).
Active on
Active pulse
Contact type: Fault signalling contact
(only, when NAMUR function = off)
Active on = active for as long as an error is present.
Active pulse = active for 1 second when an alarm signal occurs
Chemoclean is always an
"Active closed" contact Note in display
(only, when CCC and CCW are selected in field "Contact functions")
With the Chemoclean function, the valves of the CYR10 injector are effected with
an "Active closed" contact.
CHOICE
(default = bold) INFO