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7 The pH combination electrode
7.2
Cleaning
The ion-sensitive glass membrane of the combination electrode can be rinsed
under lukewarm water. Heavier contamination can be removed by using a soft
cloth with a mild domestic detergent.
Combination electrodes must never be cleaned with abrasive cleaners
(scouring powder or liquid or similar) or an abrasive sponge!
Protein deposits on the sensor portion of the combination electrode can be
cleaned off by immersion in 0.1 mol hydrochloric acid for at least 5 minutes.
Protein cleaning agents (pepsin solution) may also be used.
7.3
Operating life
The operating life of electrodes depends on the conditions in which they are
used. The operating life is at least 6 months under normal conditions and with
appropriate care and maintenance.
7.4
General handling of pH combination electrodes
- Store in a dry room at a temperature between 10°C and 30°C.
Below 0°C the combination electrode can be destroyed by freezing of the
electrolyte!
- The sensor portion of the combination electrode should be protected
against drying out by using a protective cap filled with 3-mol KCl solution or
a storage holder.
Lengthy storage in de-ionized (distilled) water will result in a depletion of the
KCl within the combination electrode.
- Remove bubbles in the membrane ball by a sharp flicking action (like
shaking down a glass thermometer).
- It is neither necessary nor possible to top up the electrolyte for these
combination electrodes (low-maintenance).
- Rinse the electrode carefully with de-ionized (distilled) water before making
a measurement.
- When measuring in different media, rinse thoroughly each time.
- Clean the combination electrode after use.
Industrial and municipal wastewater, electroplating,
painting, general contaminated media, etc.
JUMO ecoLine pH, 2 m fixed connecting
cable and BNC connector
201030/51-10-07-40-2000-76-120/052,
837
TN 20/00532380