Pentair POINT FOUR RIU3 Guía De Instalación Y Del Usuario página 22

22
Membrane Replacement
The probe's membrane should be wiped clean from time to time.
Membrane replacement should only be performed if:
• The membrane is damaged
• After long use (years), you cannot calibrate up to the correct value
• The probe is not completely full.
To replace the membrane proceed as follows. The procedure will
completely renovate the probe:
1) Remove the probe, rinse it and unscrew the cap. If it sticks, tap the
side of the probe gently with a hammer then try again. Discard the
electrolyte, rinse the cap and top part, clean off any brown or black
oxide deposits. Note that the used electrolyte will be very dark.
2) Inspect the anode. If the probe was filled correctly when it was last
renovated it will be easy to clean the dark deposits from the anode
using a nail brush or similar. If the probe was not filled completely
the anode will be very corroded and must be replaced. Check that
the nut under the anode is tight before fitting a new anode. Wash
the anode in soapy water before use to remove any protective oil.
Make sure that you use type 3 anodes on the probe, unless you
have a special probe with type 4 anode.
3) Check the cathode and remove any deposits using the plastic
abrasive pad supplied with the probe or a little wet or dry emery
paper, grade 600. The cathode MUST NOT BE POLISHED.
4) Rinse and dry the top part.
5) We advise that you perform the following easy "Dry Probe Check"
on the probe. Dry the probe completely, especially the cathode and
area around it, and observe the measurement or output signal.
The probe should have zero output. You can also measure on the
probe leads. When the probe is completely dry there should be no
voltage (mV) between the brown and blue leads. If the probe has a
temperature sensor the resistance value should be correct. Contact
OxyGuard or your distributor if this is not the case.
6) Fill a new (or renovated) cap to the brim with electrolyte. The
excess electrolyte helps remove any air bubbles. Use type 3
electrolyte (unless you have a special probe with type 4 chemistry).
The cap is renovated by fitting a new membrane and O-ring, see
below.
POINT FOUR™ RIU3™ Remote Monitor/Controller Installation and User's
Guide