Section 3 Electrode Maintenance; Storing The Electrode - Hach PLATINUM Series Manual

Section 3 Electrode Maintenance
The Platinum Series pH electrode contains a sensing glass bulb
and a liquid reference junction optimized for performance in
difficult, cold, neutral, and low ionic strength (LIS) solutions.
This sensitive instrument has been designed to give trouble-
free use, but requires careful handling to extend longevity. This
section explains methods for conditioning, cleaning, and
storing the Platinum Series pH electrode.

3.1 Storing the Electrode

Proper electrode storage requires different approaches based on
how long the electrode will be stored, how quickly the electrode
needs to be used, and the type of sample being measured.
Storage affects the reference electrolyte gel, the Ag/AgCl
reference element, and the pH sensing glass bulb.
Intermittent storage: Between uses, store the electrode in
solutions of similar ionic strength and pH to the samples of
interest. Before measuring a new sample, refresh the reference
electrolyte gel by clicking the dispenser until fresh gel emerges.
Carefully rinse the electrode to prevent sample contamination.
Overnight storage: Store the electrode in Hach pH electrode
storage solution to keep the electrode hydrated. The KCl will
not leach excessively from the electrolyte gel overnight. Prior
to use, click the electrolyte gel dispenser. A dilute gel/storage
solution will initially be ejected from the reference junction
tube. The reference gel of thicker viscosity will follow.
Eliminating the dilute gel/storage solution will guarantee
continuity of the reference junction with the sample. Blot the
reference junction with a tissue to clearly see that the
electrolyte gel, not gel diluted with storage solution, is
emerging.
Longer-term storage: To store electrodes for longer periods,
soak the electrode in storage solution (Overnight storage,
above) and re-establish gel at the reference junction on a daily
basis to keep the electrode ready for use. If the electrode soaks
for longer periods without purging the diluted electrolyte, the
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