Xylem SI Analytics PL-S 82-225pHT VP ProcessLine Manual De Instrucciones página 21

pH - und Redox – electrodes
limits of the specified ranges of use should be increased adequately. In view of an accurate
calibration we recommend the use of our hot-steam sterilised, certified buffer ampoules to
DIN 19266. Please make sure to use fresh buffer solution only.
Measuring the Redox voltage
In the case of metal single-rod measurement chains, an Ag/AgCl reference system is used
as a standard. A calibration is not necassary. Redox test solutions are available to check the
results.
Storage and maintenance
The electrodes should be stored at temperatures between 0 and 40°C. Depending on the
storage conditions (temperature and air humidity) the storage fluid contained in the irrigation
cap may dry up prematurely. This means that this fluid is to be topped up in time to prevent
the electrode from drying out. In the case of pH single-rod measurement chains/redox
measurement chains and reference electrodes, the electrolyte ought to be topped up or
replaced occasionally. Any crystals in the electrolyte space can be dissolved by warming
them in a water bath. Subsequently, please replace the electrolyte solution.
Cleaning
Contamination on the membrane/Pt sensor and diaphragm will lead to measurement
deviations. To remove it, please proceed as follows:
• To remove deposits, please use diluted mineral acids (e.g. diluted hydrochloric acid).
• Organic contaminations can be removed using appropriate suitable solvents or alkaline
solutions.
• Grease should be removed with tenside solutions or alcohol.
• Proteins with hydrochloric pepsine solution (cleaning solution L 510).
During maintenance, please observe the following items:
• After cleaning, the electrodes should be rinsed with distilled water; please do not rub dry.
• To restore ceramic diaphragms blocked from outside to proper working order, please
rub them carefully down using fine-grained sandpaper or a diamond file. Take care to not
scratch the pH glass membrane!
• Platinum diaphragms should never be exposed to any physical treatment. They may be
cleaned using chemical agents (e.g. with diluted hydrochloric acid), followed flushing
them free (e.g. by vacuuming).
• To clean ground diaphragms, please lift them gently, then slip the ground sleeve onto the
ground core.
• The glass membrane should be cleaned by rubbing it off with a fluff-free cloth soaked in
ethanol.
• When using aggressive cleaning agents, please be sure to use protective glasses and
protective gloves.
• After cleaning the electrode should be stored in 3M KCl-solution for at least 1h.
Quality
All electrodes have to comply with the strict quality requirements of final testing. Their
working life highly depends on the usage conditions. Extreme conditions such as high or
frequently alternating temperatures, strong acids and caustic solutions, protein-containing or
heavily contaminated solutions, as well as electrode poisons such as sulphides, bromides
and iodides will shorten their useful life. Apart from that, hydrofluoric acid, sodium hydroxide
and hot phosphoric acid would attack glass.
Note on the use in potentially explosive locations
ATEX identification: ATEX II 1/2G Ga/Gb Ex ia IIC T3/T4/T6
Approval according to EG type-examination certificate: PTB 08ATEX2021.
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