Crison 50 50 Guia De Inicio Rapido página 10

pH electrode 50 50
Introduction
The 50 50 is a universal pH electrode to be used with the CRISON
portable PH 25 and PH 25 DL. 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 samples
must be slightly stirred. The stirring speed should be identical in
both cases. In fi eld measurements, these types of electrodes allow
stirring the sample directly holding the electrode 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 im-
mersed 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 suffi cient. The most suitable cleaning solu-
tion is which acts in a most selective way over the contamination
(see CRISON regeneration solutions).
• Re-hydration. A "dry" electrode recovers by immersing it in CRI-
SON cleaning electrode solution, code 96 00, or in diluted HCl
solution for several hours. It is recommended to read the informa-
tion 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.
.