GENERAL OPERATIONS
13
6.3. PROBE MAINTENANCE
The silver cathode should always be bright and untarnished. If it
is tarnished or stained, the cathode should be cleaned gently with
a lint-free cloth.
y
Rinse the probe with deionized or distilled water.
y
Replace the membrane cap using fresh electrolyte. See
PROBE PREPARATION procedure.
y
Recalibrate the meter.
Membrane Maintenance
For accurate and stable measurements, perfect condition of the
membrane surface is needed. Protect the thin membrane from
scratches, abrasion or contact with solids.
If no measurements are taken for a few hours, protect the
membrane with the plastic protective cap.
If fouled, rinse it carefully with distilled or deionized water. If
damaged, replace the membrane cap.
Note: Change the membrane every 8 weeks or more frequently
if used in a specially fouling environment. Check and replace
the electrolyte fill solution every 4 weeks.
Storage
After taking the measurements, switch the meter off and clean the
probe before storage. When not in use the probe should be stored
with the plastic protective cap on.
For short term storage, the probe can also be stored in a beaker of
deionized water with the protective plastic cap removed.
For long term storage, the probe should be stored dry:
1. Disconnect the probe from the meter
2. Unscrew the membrane cap
3. Remove any electrolyte solution from the cap
4. Rinse the probe anode/cathode assembly with distilled water
and blot dry
5. Screw the membrane cap onto the probe until the membrane
cap is hand tight
