Hanna Instruments pH 209 - Manual (Page 7)

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Follow the Storage Procedure above.
CLEANING PROCEDURE
General Soak in HI 7061 general cleaning solution for approxi-
mately 30 minutes.
Removal of films, dirt or deposits on the membrane/junction:
-
Protein Soak in HI 7073 protein cleaning solution for 15 min.
- Inorganic Soak in HI 7074 inorganic cleaning solution for 15
minutes.
- Oil/grease Rinse with HI 7077 Oil & Fat cleaning solution.
IMPORTANT: After performing any of the cleaning procedures rinse
the electrode thoroughly with distilled water, refill the reference cham-
ber with fresh electrolyte (not necessary for gel-filled electrodes) and
soak the electrode in HI 70300 storage solution for at least 1 hour
before taking measurements.
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 fresh HI 7071 for single junction or
HI 7082 for double junction electrodes.
• Dry Membrane/Junction: soak in HI 70300 storage solution for
at least 1 hour.
• Drifting: soak the electrode tip in warm (approx. 50-60°C)
Hanna HI 7082 solution for one hour and rinse the tip with
distilled water. Refill with fresh HI 7071 for single junction
electrodes and HI 7082 for double junction electrodes (refillable
electrodes only).
• Low Slope: refer to the cleaning procedure above.
• No Slope: check the electrode for cracks in glass stem or bulb
and replace the electrode.
• Slow Response/Excessive Drift: soak the tip in HI 7061
solution for 30 minutes, rinse thoroughly in distilled water and
then follow the Cleaning Procedure above.
For refillable electrodes:
If the filling solution (electrolyte) is more than 2½ cm (1") below the
fill hole, add HI 7082 3.5M KCl electrolyte solution for double junction
or HI 7071 3.5M KCl+AgCl electrolyte solution for single junction
electrodes.
For a faster response, unscrew the fill hole screw during measure-
ments.
For AmpHel ® electrodes:
If the electrode does not respond to pH changes, the battery is run
down and the electrode should be replaced.
MEASUREMENT
Rinse the electrode tip with distilled water. Immerse the tip (bottom 4
cm /1½") in the sample and stir gently for a few seconds.
For a faster response and to avoid cross contamination of the samples,
rinse the electrode tip with a few drops of the solution to be tested,
before taking measurements.
STORAGE
To minimize clogging and assure a quick response time, the glass bulb
and the junction should be kept moist and not allowed to dry out.
Replace the protective cap with a few drops of HI 70300 storage
solution or, in its absence, electrolyte solution (HI 7071 for single
junction, or HI 7082 for double junction electrodes). Follow the
Preparation Procedure above before taking measurements.
NEVER STORE THE ELECTRODE IN DISTILLED OR DEIONIZED WATER.
PERIODIC MAINTENANCE
Inspect electrode and cable. The cable used for connection to the
meter must be intact and there must be no points of broken
insulation on the cable or cracks on the electrode stem or bulb.
Connectors must be perfectly clean and dry. If any scratches or cracks
are present, replace the electrode. Rinse off any salt deposits.
For refillable electrodes:
Refill the reference chamber with fresh electrolyte (HI 7071 for single
junction or HI 7082 for double junction electrodes). Allow the electrode
to stand upright for 1 hour.