13
12
For refillable electrodes
If the filling solution (electrolyte) is more than 2.5 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 solution in the protective cap with a few drops of
HI 70300
storage solution or, in its absence, filling solution (
HI 7071
for single junction or
HI 7082
for double junction electrodes). 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 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
for single
junction or
HI 7082
for double junction electrodes). Allow the elec-
trode to stand upright for 1 hour.
Follow the Storage Procedure above.
AmpHel
®
is a registered Trademark of "Hanna Instruments"
ELECTRODE CONDITIONING & MAINTENANCE
PREPARATION
Remove the protective cap.
DO NOT BE ALARMED IF SALT DEPOSITS ARE PRESENT. This is normal
with electrodes and 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
HI 70300
storage solution for at least one hour.
Note:
To prevent damage to the pH electrode, remove it from the
solution before turning the meter off.
With the meter OFF, detach the electrode from the instrument
and immerse it in the storage solution.
