Crison 50 52 Manual Usuario página 10

pH electrode 50 52
Introduction
The 50 52 is a pH electrode, with large ring diaphragm of PTFE, to
be used with the CRISON portable PH 25 and PH 25 DL.
These are low maintenance electrodes, as they do not require moni-
toring of electrolyte levels.
This model is supplied with a "working protector", protecting the
electrode against knocks.
Electrode preparation
Remove the storage protector containing electrolyte by unscrewing it
and put the working protector on its place (see Fig. A).
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.
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 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.
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 response
appropriately after regeneration, must be replaced by a new one.
If an electrode has too short life span, less than three months,
ask us about it. Probably there are more suitable electrode for the
application.
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clean.
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