Crison pH 52 22 Manual Usuario página 10

pH electrode 52 22
Introduction
The 52 22 is a pH electrode with screw cap S7,
suitable for difficult samples up to pH 14.
Electrode preparation
Remove the storage protector containing
electrolyte by unscrewing it
Verify that there are not air bubbles inside
the membrane
by shaking the electrode as a clinical ther-
mometer.
Remove the cap from the filling port
Before measuring, slide the plastic ring
and return it to its original position, by press-
ing softly, to ensure the electrical contact.
Calibration
See pH-meter instruction manual.
Measurements. Recommendations
• During calibration and measurement the
buffers and the samples must be slightly
stirred. The stirring speed should be iden-
tical in both cases.
• The sample must cover at least the lower
border of the electrode's diaphragms
• After measurement, rinse the electrode with
distilled water. Dry it with soft tissue, only by
contact, without rubbing.
• Between measurements the electrode's
membrane should be immersed in aqueous
solution. The most appropriate place is the
storage protector with some electrolyte.
Do not leave the electrode immersed in
distilled water.
Maintenance
• Periodically refi ll the electrode with electrolyte.
Maintain the level as high as possible
• Maintain the membrane's surface clean
Protect it from friction or knocking.
• When an electrode gets contaminated, the
simple rinsing with distilled water is not suf-
fi cient. The most suitable cleaning solution
is one which acts in a more selective way
over the contamination.
• Re-hydration. A "dry" electrode recovers by
immersing it in CRISON cleaning electrode
solution, code 96 00, or in diluted HCl solu-
tion for several hours. It is recommended to
read the information supplied with the elec-
trode's regenerating solutions.
Troubleshooting
... the pH-meter always measures the same
pH value.
Short circuit in the electrode or connector.
Substitute the electrode.
... unstable reading.
Air bubble in the membrane.
Shake the electrode as a thermometer.
... impossible to perform calibration.
... very slow response.
Dirt on the diaphragm or the membrane.
De-hydrated membrane.
Electrode ageing or wear.
Clean, regenerate, substitute electrode.
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