Hanna Instruments HI 2002, Instruction Manual, Page: 43 / 52

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Remove the protective cap of the pH electrode.
DO NOT BE ALARMED IF SALT DEPOSITS ARE PRESENT.
This is normal with electrodes. They will disappear when rinsed with water.
During transport, tiny bubbles of air may form inside the glass bulb affecting proper functioning of
the electrode. These bubbles can be removed by “shaking down” the electrode as you would do with
a glass thermometer. If the bulb and/or junction is dry, soak the electrode in
HI70300 or HI80300
storage solution for at least one hour.
For refillable electrodes:
If the filling solution (electrolyte) is more than 2½ cm (1”) below the fill hole, add
HI7082 or
HI8082 3.5M KCl Electrolyte Solution for double junction electrodes.
Unscrew the fill hole cover during measurements so the liquid reference junction maintains an
outward flow of electrolyte.
Measurement
Rinse the electrode tip with distilled water. Submerse the tip 3 cm (1¼”) 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 Procedure
To minimize clogging and ensure a quick response time, the glass bulb and the junction should be
kept moist and not allowed to dry out.
MAINTENANCE
Replace the solution in the protective cap with a few drops of HI70300 or HI80300 Storage Solution
or, in its absence, Filling Solution ( HI7082 or HI8082 for double junction electrodes).
Follow the preparation procedure 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 connection to the instrument 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 (
HI7082 or HI8082 for
double junction electrodes). Allow the electrode to stand upright for 1 hour.
Follow the Storage Procedure above.