LF 170
Operation
109
ba54104e09
11/2010
Invalid setting
With the
700
,
600
and
300
sensor types, the entry is invalid if the
value deviates from the nominal cell constant by more than ±10 %:
If the validity range is left, this is already visible from the flashing sensor
symbol during the setting process:
Measurement is not possible with an invalid setting. After swapping to
the measured value display the sensor symbol and an invalid
measured value are displayed ("----"). The states of all relays and
current outputs linked with the measured conductivity value remain
frozen.
Remedial measures:
z
Clean the measuring cell (see measuring cell operating manual)
z
Check the conductivity control standard and renew if necessary
z
Then repeat the checking/setting routine.
If these measures are not successful or cannot be carried out and a
further measurement is still required, the checking/setting routine can
be repeated and a valid value selected for the cell constant. However
note that the subsequent measured values contain a larger measuring
error and the measuring system no longer meets the stated
specifications.
Sensor
type
Validity range
700
0.826 ... 1.008 cm
-1
(0.917 cm
-1
±10 %)
600
0.826 ... 1.008 cm
-1
(0.917 cm
-1
±10 %)
300
0.549 ... 0.669 cm
-1
(0.609 cm
-1
±10 %)
cm
S/
cm
1/
4
0
6
9
2
1
3
1
Tref25
Sensor symbol
