20 of 21 INST.21
Electrode Storage
To ensure that the electrode gives a rapid response, the tip of the
electrode and the liquid junction must not be allowed to dry out. Care
should be exercised therefore when storing the electrode between use.
For short-term storage between measurements of up to one week,
keep the electrode dipped in Palintest Electrode Storage Solution. If
this solution is not available, use water containing a small amount of
potassium chloride.
Do not leave the electrode standing in
deionised water.
For long-term storage of more than one week, replace the electrode
tip in the protective bottle cap, the bottle cap should contain Palintest
Electrode Storage Solution. When returning the electrode to use
prepare it as for a new electrode.
Cleaning the Electrode
If the electrode becomes dirty it can be cleaned by one of the
following procedures :-
General Cleaning
- Soak the electrode in 0.1M hydrochloric acid for
one hour.
Inorganic Deposits
- Soak the electrode in 0.1M EDTA tetrasodium
salt for 15 minutes.
Oil and Grease
- Rinse the electrode in methylated spirits or alcohol
solution. In severe cases the liquid junction may become completely
clogged with grease. In such cases the electrode should be replaced.
Protein
- Soak the electrode in a solution of 1% pepsin in 0.1M
hydrochloric acid for 15 minutes.
After performing any of the above cleaning procedures, thoroughly
rinse the electrode with deionised water. Stand the electrode in
Palintest Electrode Storage Solution for at least one hour before use.
Trouble-Shooting Guide
If the pH meter will not give a steady reading, or fails to give a reading
of the expected value, check that the meter is being operated in
accordance with the instructions supplied then investigate the
electrode status.
