Hanna Instruments HI 903, Quick Start Manual

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8-8
MAINTENANCE, PERIPHERALS
8.2 Probe Maintenance
Proper probe maintenance is crucial for reliable measurements and extending the life of
the probe. The frequency of maintenance will depend largely on the type of
samples that are analyzed. Maintenance may be required if any of the following are
observed:
· Slow or no electrode response;
· Noisy mV readings;
· Debris on or between electrode pins
· Coating on electrode pins
If these signs are observed, the electrode pins may be dirty. Rinse the electrode with a
solvent that is appropriate for the type of sample used – methanol is usually
sufficient. Allow the probe to dry completely before re-installing.
If a more thorough cleaning is required, soak the electrode in HI 7061 Electrode Cleaning
Solution for General Use for several hours, then rinse with water followed by
methanol. Allow to dry before re-installing.
After allowing the probe to dry, inspect the glass cracks, especially near the electrode pins.
Replace the electrode if any cracks are found.
Warning: Take care to protect the electrode pins from damage! Avoid using brushes/
abrasives to clean the pins. Pins can easily bend, which will cause permanent errors
in mV readings!