wtw Oxi 170, Operating Instructions Manual

Page: 37 / 64

Oxi 170 Operation
99 ba24105e08 11/2010
4.6.3 Timer for external sensor cleaning system
Function The cleaning function enables the timing of a sensor cleaning system
through one relay of the monitor. The relay always works as a closer
(normally open).
Setting table for sensor cleaning:
Note
No calibration is possible during the cleaning process (
tc
) and the
adjustment duration (
th
). If a cleaning process is due during a running
calibration, the start is delayed until the calibration is completed. The
starting time of all subsequent cleaning processes is moved back
according to the delay.
Setting Selection/Values Explanation
Tr
1 ... 168
(hours) Time interval between two cleaning
processes
tc 10
...
300
(seconds)
Duration of the cleaning process. During the
cleaning process the measured value is
frozen.
th 10
...
900
(seconds)
Time for adapting the sensor to the
measured medium after the cleaning
process. During the adaptation period the
measured value is frozen.
Operating notes on setting the numerical
values:
– Set the first (flashing) digit with
<UP><DOWN> and confirm with
<ENTER> .
– Set the other digits in the same way.
– After the last digit you reach the next
setting
– After entry of all three values the setting of
the sensor cleaning is complete