P Re - Polarization - UNISENSE SULF Series User Manual

• Once the correct polarization (see above) is
S
entered, press
elect
The sensor is now polarized .
Setting polarization on the PA2000
If you are using the legacy PA2000 please consult the PA2000
manual, which is available on www .unisense .com/manuals
If you are using another amplifier or sensor connection type,
please check the polarization voltage before connecting a sensor,
since incorrect polarization may destroy the sensor .
For details on how to set the polarization, consult the user manual
of the amplifier that you are using .
p -
re polarization
A period of polarization is necessary before you can use the sensor .
This is called the pre-polarization period . If the sensor is new or has
not been operated for several days, it must be pre-polarized for at
least 2 hours before it can be calibrated and used . After shorter
periods without polarization, the sensor should be pre-polarized
until it has shown a stable signal for at least ten minutes . When
pre-polarization is initiated, the signal will be very high and
then drop rapidly over the first few minutes . After that, the
signal will drop slowly for up to two hours (for needle- and some
custom-made sensors slightly longer) . It takes normally between
10 minutes and an hour before a sensor is stable . The sensor signal
depends on the specific sensor (see the delivery note which came
with the sensor) . If the signal does not stabilize or is too high or
too low, refer to the 'Troubleshooting' section .
.
IMPORTANT
Calibration must
be performed after
pre-polarization
when the sensor
signal has
stabilized.
Always use
a calibration
solution with the
same temperature
and salinity as the
sample solution.
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