horiba LAQUA-PH1500, Instruction Manual

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Maintenance and Storage
34
● Maintenance and Storage of pH and ORP Electrodes
This section describes an overview of the procedures for maintenance and storage of pH
electrode.
● How to clean the electrodes
When the tip of an electrode (responsive membrane and liquid junction) becomes dirty, the
response time may slow or an error may occur in the measurement results. To avoid such
errors, clean the electrode. For dirt that cannot be washed off by pure water (or deionized
water), use the cleaning solution indicated below depending on the type of dirt. After cleaning,
rinse the electrode with pure water (or deionized water).
However for pH and ORP electrodes, different cleaning solutions should be used to clean
different types of dart.
For pH electrode
For ORP electrode
Type of dirt Cleaning solution
General Diluted neutral cleaning solution
Oil Alcohol, or diluted neutral cleaning solution
Inorganic substance 1 mol/L HCl or electrode cleaning solution
Protein Cleaning solution including protein-removing enzyme
Alkali Dip in 1 mol/L HCl or electrode cleaning solution for 1h to 2 h
Type of dirt Cleaning solution
General
Dilute neutral cleaning solution (General dish washing liquid
works reasonably well.) Oil
Inorganic substance Immerse dilute nitric acid (1:1 nitric acid)