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CLEANING PROCEDURE
General
Soak in Hanna
HI 7061
General Cleaning Solu-
tion for approximately ½ hour.
Removal of films, dirt or deposits on the membrane/junction:
Protein
Soak in Hanna
HI 7073
Protein Cleaning Solu-
tion for 15 minutes.
Inorganic
Soak in Hanna
HI 7074
Inorganic Cleaning
Solution for 15 minutes.
Oil /grease
Rinse with Hanna
HI 7077
Oil and 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 necessary for gel-filled
electrodes) and soak the electrode in
HI 70300
Storage Solution for
at least 1 hour before taking a measurement.
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 Storage Solution
HI 70300
for at least 1 hour.
•
Drifting:
Soak the electrode tip in warm Hanna Solution
HI 7082
for one hour and rinse tip with distilled water (refill with
fresh
HI 7071
for single junction electrodes and
HI 7082
for
double junction electrodes if necessary).
•
Low Slope:
Refer to the cleaning procedure above.
•
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 dam-
aged nor lying in a pool of water or solution.
•
Slow Response/Excessive Drift:
Soak the tip in Hanna Solu-
tion
HI 7061
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
abrasive paper (paying attention not to scratch the surface) and
wash thoroughly with water.
If the bulb and/or junction are dry, soak the electrode in
HI 70300
Storage Solution
for at least one hour.
For refillable electrodes:
If the refill 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 AmpHel
®
electrodes:
If the electrode does not respond to pH changes, the battery is run
down and the electrode should be replaced.
TEST MEASUREMENT
Rinse the electrode tip with distilled water.
Immerse the tip (bottom 4 cm / 1½") in the sample and stir gently
for approx. 30 seconds.
For a faster response and to avoid cross contamination of the samples,
rinse the electrode tip with the solution to be tested, before taking
your 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.
When not in use, replace the solution in the protective cap with a few
drops of
HI 70300
Storage Solution or, in its absence,
HI 7007
pH 7.01 Buffer Solution.
Follow the Preparation Procedure above before taking measurements.
Note:
NEVER STORE THE ELECTRODE IN DISTILLED OR DEIONIZED
WATER.
PERIODIC MAINTENANCE
Inspect the electrode and the cable. The cable used for the 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 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 Storage Procedure above.
AmpHel
®
is a registered Trademark of "Hanna Instruments"
