18
ELECTRODE PREPARATION
PREPARATION PROCEDURE
Remove the electrode protective cap.
DO NOT BE ALARMED IF ANY SALT DEPOSITS ARE PRESENT. This is normal with electrodes and
they will disappear when rinsed with water.
During transport tiny bubbles of air may have formed inside the glass bulb. The electrode cannot
function properly under these conditions. These bubbles can be removed by "shaking down" the
electrode as you would do with a glass thermometer.
If the bulb is dry, soak the electrode in
HI 70300
Storage Solution for at least one hour.
Preparation of reference electrode:
• Unwrap Parafilm
TM
seal found over ceramic junction
on inner stern of the reference electrod and discard.
This is only used for shipping.
• Rinse inner stern with deionized water making cer-
tain to wet o-ring found on the inner stern.
• Reassemble reference electrode by gently pushing
the inner assembly into the outer body, sliding spring
down cable, and screwing cap into place.
• Remove fill hole cover and o-ring or fill hole spout.
• Using the dropper pipette provided, add a few drops
of
HI 7072
filling solution to the reference electrode,
wetting the o-ring and rinsing out the fill solution
chamber.
• Holding the body of the electrode depress the black cap with your thumb. This permits the
fill solution to drain out of the body. Verify if the electrode returns to its original position.
(You may need to gently assist for this to occur).
• Tighten the electrode cap onto the body and fill electrode body with
HI 7072
filling solution
until fill solution volume is just below fill hole.
Note:
During measurement always operate reference electrode with the fill hole open.
MEASUREMENT
Place pH electrode and reference electrode into electrode holder and connect the Cable
Connectors to the instrument.
Rinse the pH and reference electrodes tip with distilled or deionized water. Immerse the pH and
reference electrodes (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.