Hach 50 12 T Manual Del Usuario página 10

pH electrode 50 12 T
Introduction
The 50 12 T is a high performance pH electrode for aqueous me-
dia in general, with built-in A.T.C. Pt 1000.
Electrode preparation
Remove, by unscrewing it, the storage protector containing
electrolyte .
Remove the air bubbles that are inside the membrane
They can be removed by shaking the electrode as a clinical
thermometer.
Remove the cap from the electrolyte filling port
Calibration
See pH-meter instruction manual.
Measurements. Recommendations
• During calibration and measurement the buffers and the sam-
ples must be slightly stirred. The stirring speed should be iden-
tical in both cases.
• The sample must cover the electrode's diaphragm
• After measurement, immediately rinse the electrode with dis-
tilled water. Dry it with soft tissue, only by contact, without rub-
bing.
• 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 refill the electrode with electrolyte. Maintain the
level as high as possible
• Maintain the membrane's surface clean
tion or knocking.
• When an electrode gets contaminated, the simple rinsing with
distilled water is not sufficient. The most suitable cleaning solu-
tion is one which acts in a more selective way over the contami-
nation (look for HACH regeneration solutions).
• Re-hydration. A "dry" electrode recovers by immersing it in
HACH cleaning electrode solution, code C20C370, or in di-
luted HCl solution for several hours. It is recommended to read
the information supplied with the electrode's regenerating solu-
tions.
Troubleshooting
... always measures the same pH value.
Short circuit in the electrode or cable.
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 or substitute the electrode.
Storage
Place the electrode in the storage protector
KCl 3M Sat. AgCl.
Close the refilling port with the stopper
Life of an electrode
The average life expectancy of a pH electrode is approximately
one year depending on the working conditions.
An electrode used for more than six months that does not re-
sponse appropriately after regeneration, must be replaced by a
new one.
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