Z03.0.0X.6C-11
Operating manual GE xxx serie
page 9 of 12
4.3 Care and maintenance
For electrodes with liquid electrolyte: Check level of reference electrolyte and, if necessary, refill
3 mol/l KCl solution with help of an syringe or pipette
.
Normal cleaning takes place with the GRL 100 pepsin cleaning solution into which the electrode
is immersed for 5 - 10 minutes before being rinsed off with clean water.
Crystallisation of the 3 mol/l KCL solution is unavoidable. Crystallised potassium
chloride on the protective cap and shaft can easily be removed with a fingernail or
cloth and is therefore not a defect or grounds for complaint.
Dirty electrodes must be cleaned. The suitable cleaning agents for the pH glass membrane are
listed in the table below.
Mechanical cleansing should be avoided as this might damage the electrode permanently.
Therefore a chemical cleansing is preferable.
Impurities
Cleaners
General residue
Mild detergent
Inorganic coatings
common fluids for glass cleaning
Metal compounds
1 mol/l HCl solution or GRL 100 pepsin cleaning
solution
Oil and grease
Special cleaner or solvent
Biological coatings with protein
1% pepsin enzyme in 0.1 molar GRL 100 HCl
solution
Biological coatings with protein
Acetone
Extremely resistant residues
Hydrogen peroxide or sodium hypochloride
The material of the pH probe must always be protected. Plastic shafts must not be cleaned in
solvents, etc. If in doubt, contact the manufacturer to inquire about suitable cleaners for the existing
electrode. This is also important in the case of aggressive substances or other substances that are
not primarily water-based!
The GAK 1400 working and calibration set includes all necessary products for
calibration, care and maintenance of the electrode.
