5.4.2
Check
Polarisation detection
Polarisation effects in the interface between
electrode and measuring solution limit the
measuring range of conductive conductivity
measuring cells. The Liquisys M transmitter
has the ability to detect polarisation effects
using an intelligent signal evaluation process.
PCS alarm (Process Check System)
This function is used to examine the measuring
signal for deviations. If the measuring signal
is constant for a specific period of time (several
measured values), an alarm is issued. This
type of measuring cell behaviour may be
caused by soiling, etc.
Note:
A current PCS alarm is automatically
deleted as soon as the sensor signal
changes.
LIVE.CDR
Constant meas. signal
= alarm is triggered
t
Fig. 5.4
PCS alarm (live-check)
Coding
Field
Selection or range
Factory setting
Display
Info
P
Function group
CHECK
(S version only)
Settings for measuring cell and
process monitoring.
P1
Switch polarisation
detection on or off
(conductive only)
off
on
Polarisation only occurs with
conductive measuring cells.
Polarisation is detected but not
compensated.
(Error no.: E071.)
P2
Set PCS alarm
(live-check)
off
1h
2h
4h
This function is used to examine
the measuring signal. An alarm is
signalled if it does not change for
the period selected here.
Monitoring limit: 0.3 % of mean
value over selected period.
(Error no.: E152.)
Factory settings are printed in
bold
face;
base version does not include functions in italics.
P
CHECK
P1
Pol.Detec
off
P2
PCS Alarm
off
Instrument configuration
Liquisys M CLM 223 / 253
30
Hauser