Crison MultiMeter 44 Manual Del Usuario página 48

Operation
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5. Ensure that the membrane is tightly screwed. The first screw-in resistance is due to
the internal O-ring seal. However, it is necessary to continue screwing until the
electrode shaft is reached
Note: It is recommended to verify the correct installation of the membrane in 1 hour after the sensor
has been in run.
6. Please the silicone O-ring over the hole for electrolyte outlet and remove the excess
with some water.
7. Install the electrode in the process.
8. The required polarization time is 1 hour. After this period, the electrode can be
calibrated. It is recommended to recalibrate in 24 hours the system and periodically
verification of its functioning.
Important notes:
Before unscrewing/screwing the membrane ensure that the hole for electrolyte outlet
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is open. For this, remove the silicone O-ring. Otherwise, the membrane will be
damaged due to vacuum building up in the membrane cap.
Before installing the electrode in the process ensure that the hole for electrolyte outlet
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is perfectly closed with the silicone O-ring.
Sensor installation
Recommended installation: in a flow through chamber 60 05 (see
Measurement
The required polarization time is 1 h.
The recommended flow of the water is approx. 30l/h.
Calibration
The calibration is carried out against DPD-1 colorimetric method.
Sensor maintenance
Note: The sensor can not stand dry.
When the electrode in not in use it is recommended to dismount the membrane and store
the sensor and the membrane clean and dry. Before installing again the electrode it is
necessary to clean the electrode tip (working electrode) with an abrasive paper. If there is
some layer of lime over the membrane it can be eliminated by immersing the membrane in
diluted acid solution. After wards clean with distilled water.
Life span of the membrane: The membrane life is typically one year, but it can vary
depending on the water quality. This electrode can not be used in heavy contaminated
water.
When the calibration is impossible due to instable readings or too low readings, it is
necessary to substitute the electrolyte.
Remove the silicone O-ring from the hole for electrolyte outlet. It must be open.
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Unscrew the membrane
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Clean the internal sensor with soft and dry tissue.
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Clean the sensor tip (working electrode) with abrasive paper (rubbing).
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Figure 24, Page 43)