Hanna Instruments HI 9023C Instruction Manual page 14

For refillable electrodes:
If the filling solution (electrolyte) is more than 2½ cm (1") below the
fill hole, add HI 7082 or HI 8082 3.5M KCl Electrolyte Solution for
double junction or HI 7071 or HI 8071 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 solution in the protective cap with a few drops of HI 70300
or HI 80300 Storage Solution or, in its absence, Filling Solution
(HI 7071 or HI 8071 for single junction or HI 7082 or HI 8082 for
double junction electrodes). Follow the Preparation Procedure above
before taking measurements.
Note: NEVER STORE THE ELECTRODE IN DISTILLED OR DEIONIZED WA-
TER.
PERIODIC MAINTENANCE
Inspect the electrode and the 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 with
water.
For refillable electrodes:
Refill the reference chamber with fresh electrolyte (HI 7071 or HI 8071
for single junction or HI 7082 or HI 8082 for double junction elec-
trodes). Allow the electrode to stand upright for 1 hour.
Follow the Storage Procedure above.
AmpHel is a registered Trademark of "Hanna Instruments"
®
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CLEANING PROCEDURE
Soak in Hanna HI 7061 or HI 8061 General Clean-
General
ing Solution for approximately ½ hour.
Removal of films, dirt or deposits on the membrane/junction:
Soak in Hanna HI 7073 or HI 8073 Protein Clean-
- Protein
ing Solution for 15 minutes.
Soak in Hanna HI 7074 or HI 8074 Inorganic Clean-
- Inorganic
ing Solution for 15 minutes.
- Oil/grease Rinse with Hanna HI 7077 or HI 8077 Oil and Fat
Cleaning Solution.
IMPORTANT: After performing any of the cleaning procedures
rinse the electrode thoroughly with distilled water, refill the refer-
ence chamber with fresh electrolyte (not necessary for gel-filled
electrodes) and soak the electrode in HI 70300 or HI 80300
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 or HI 8071 for
single junction or HI 7082 or HI 8082 for double junction
electrodes.
• Dry Membrane/Junction: Soak in HI 70300 or HI 80300
Storage Solution for at least 1 hour.
• Drifting: Soak the electrode tip in warm (approx. 50-60 C)
Hanna HI 7082 or HI 8082 Solutions for one hour and rinse
the tip with distilled water. Refill with fresh HI 7071 or
HI 8071 for single junction electrodes and HI 7082 or HI 8082
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 or
HI 8061 Solutions for 30 minutes, rinse thoroughly in distilled
water and then follow the Cleaning Procedure above.
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