Thermo Fisher Scientific CyberScan PC 510 - Manual (Page 43)

Instruction Manual PC 510
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9 PROBE CARE AND MAINTENANCE
9.1 pH Electrode care
Since your pH electrode is susceptible to dirt and contamination, clean as necessary depending on the
extent and condition of use.
NOTE: For specialty electrode care, consult your electrode instruction manual .
pH electrode storage
For best results, keep the pH bulb hydrated. Use the protective electrode storage bottle or rubber cap
filled with electrode storage solution to store your electrode. Alternatively, you can store in a pH 4
buffer with 1/100 part of saturated KCl. Other pH buffers are OK for short term storage, but NEVER
use distilled water for storage.
After measuring
1. Rinse the pH electrode and reference junction in de-ionised water.
2. Store the electrode as recommended above in “pH electrode storage solution”, or as
recommended by the manufacturer.
3. Prior to next use, rinse the liquid junction with de-ionised water and tap dry – never wipe
electrode.
NOTE: If this does not restore electrode to normal response, see “Reactivating the pH electrode”
section below.
pH electrode cleaning
• Salt deposits: Dissolved the deposits by immersing the electrode in tap water for ten to fifteen
minutes. Then thoroughly rinse with distilled water.
• Oil/Grease film: Wash electrode pH bulb gently in some detergent and water. Rinse electrode tip
with distilled water or use a general purpose electrode cleaner (see ordering information).
• Clogged reference junction: Heat a diluted KCl solution to 60 to 80 °C. Place the sensing part of
the electrode into the heated solution for about 10 minutes. Allow the electrode to cool in some
unheated KCl solution.
• Protein deposits: Prepare a 1% pepsin solution in 0.1 M of HCl. Set the electrode in the solution
for five to ten minutes. Rinse the electrode with distilled water.
Reactivating the pH electrode
If stored and cleaned properly, your pH electrode should be ready for immediate use. However, a
dehydrated bulb may cause sluggish response. To rehydrate the bulb, immerse the electrode in a pH
4 buffer solution for 10 to 30 minutes. If this fails, the electrode requires activation. Never touch or rub
glass bulb. Contact builds up an electro-static charge.