Hanna Instruments mV 600 Series - Manual (Page 26)

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• No Slope:
- Check the electrode for cracks in glass stem or bulb
(replace the electrode if cracks are found).
- Make sure cable and connections are not damaged nor
lying in a pool of water or solution.
• Slow Response/Excessive Drift: soak the tip in the HI 7061
solution for 30 minutes, rinse thoroughly in distilled water
and then follow the Cleaning Procedure above.
• For ORP Electrodes: polish the metal tip with a lightly abra-
sive paper (paying attention not to scratch the surface)
and wash thoroughly with water.
Note With industrial applications, it is always recommended to
keep at least one spare electrode handy. When anomalies
are not resolved with a simple maintenance, change the
electrode (and recalibrate the controller) to see if the prob-
lem is alleviated.
For refillable electrodes**: Refill the electrode with fresh electrolyte (HI 7071 for single
junction or HI 7082 for double junction electrodes). Allow
the electrode to stand upright for 1 hour. Follow the Stor-
age Procedure above.
CLEANING PROCEDURE
General Soak in Hanna HI 7061 general cleaning
solution for approximately 30 minutes.
Removal of films, dirt or deposits on the membrane/junction:
Protein Soak in Hanna HI 7073 protein cleaning so-
lution for 15 minutes.
Inorganic Soak in Hanna HI 7074 inorganic cleaning
solution for 15 minutes.
Oil/grease Rinse with Hanna HI 7077 Oil & Fat cleaning
solution.
IMPORTANT After performing any of the cleaning procedures rinse the
electrode thoroughly with distilled water, drain and refill
the reference chamber with fresh electrolyte, (not neces-
sary for gel-filled electrodes) and soak the electrode in
HI70300 storage solution for at least one hour before rein-
stalling it.
TROUBLESHOOTING
Evaluate your electrode performance based on the following.
• Noise (Readings fluctuate up and down) could be due to:
- Clogged/Dirty Junction: refer to the Cleaning Procedure
above.
- Loss of shielding due to low electrolyte level (in refillable
electrodes only): refill with HI 7071 for single junction
or HI 7082 for double junction electrodes.
• Dry Membrane/Junction: soak in HI 70300 storage solu-
tion for at least 1 hour. Check to make sure the installation
is such as to create a well for the electrode bulb to con-
stantly remain moist.
• Drifting: soak the electrode tip in warm Hanna HI 7082
solution for one hour and rinse tip with distilled water (refill
with fresh HI7071 for single junction electrodes and
HI7082 for double junction electrodes if necessary).
• Low Slope: refer to the cleaning procedure above.