Hach 50 50 Guia Del Usuario página 10

pH electrode 50 50
Introduction
The 50 50 is a universal pH electrode to be used with the HACH
portable pH-meter. These are low maintenance electrodes, as they
do not require monitoring of electrolyte levels.
Electrode preparation
Remove the storage protector containing electrolyte by unscrewing it.
MP-5 connector (IP 67). Connect and disconnect by pushing.
Do not unscrew it.
Calibration
All pH electrodes must be calibrated with buffer solutions before
measuring.
Measurements. Recommendations
• During calibration and measurement the buffers and the sam-
ples must be slightly stirred. The stirring speed should be
identical in both cases. In field measurements, these types of
electrodes allow stirring the sample directly holding the elec-
trode by the handle.
• The sample must cover the electrode's diaphragm
• After measurement, immediately 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.
WARNING
• Do not leave the electrode immersed in distilled water.
• Do not bend the cable on the handle level.
• Never unscrew the MP-5 connector.
Maintenance
• Maintain the membrane's surface
• When an electrode gets contaminated, the simply rinsing with
distilled water is not sufficient. The most suitable cleaning solu-
tion is which acts in a most selective way over the contamina-
tion (see HACH regeneration solutions).
• Re-hydration. A "dry" electrode recovers by immersing it in
HACH cleaning electrode solution, code C20C370, or in diluted
HCl solution for several hours. It is recommended to read the
information supplied with the electrodes regenerated solutions.
Troubleshooting
... the pH-meter always measures the same pH value.
Short circuit in the electrode, cable or connector.
Substitute the electrode.
... fortuitous reading.
Broken cable.
Substitute the electrode.
... impossible to perform calibration.
... very slow response.
Dirt on the diaphragm and/or the membrane.
De-hydrated membrane.
Electrode ageing or wear.
Clean, regenerate or replace the electrode.
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See pH-meter instruction manual.
clean.
.