Endress+Hauser CA76NA, Operating Instructions Manual

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CA76NA Maintenance
Hauser 55
4. Select the Manual menu item.
5. Select the Calib. menu item.
 The analyzer performs an automatic calibration for approx. 1 h 15 min until
approx. 2 h 30 min. The automatic mode can be re-established during the
calibration. In this case, the device immediately starts automatic measurement
on completion of the calibration.
6. Press the key to open the Operating Mode menu item.
7. Select AUTOMATIC .
11.2.6 Replacing electrodes
Removing electrodes
1. The analyzer is switched off or Mode = OFF .
Unscrew the plug of the cable marked "Na+" from the sodium electrode.
2. Unscrew the plug of the cable marked "pH" from the pH electrode.
3. Loosen the electrode screw connections on the measuring unit.
4.
NOTICE
Risk of damaging the electrodes during the installation and removal procedure
‣
Exercise care when inserting the electrodes into, and removing the electrodes
from, the chambers of the flow through cell.
‣
Do not touch against the glass bulbs of the electrodes.
‣
Avoid air bubbles in the glass bulbs. If air bubbles are present, hold the electrode
in a vertical position and shake it gently to remove the bubbles.
‣
Do not allow the glass bulbs of the electrodes to become dry. Fit protection caps
on the electrodes.
Remove electrodes from the left (sodium) and/or the right (pH) chamber.
5. NOTICE
The KCl solution can damage the sodium electrodes
‣
Do not confuse the protection caps and storage solutions.
Fill the bottom sealing cap with the relevant electrode solution so that the electrodes
do not dry out. For pH: use a 3-molar KCl solution. For sodium: use min. 1000 µg/l
(ppb) sodium solution.
6. Fit the original sealing caps on the electrodes.
Preparing the new electrodes
1. Fill the measuring unit halfway with deionized water so that the electrodes do not
dry out after installation.
2. Remove the electrodes from the packaging. The sodium electrode is marked "Na" on
the shaft. The pH electrode has no marking.
3. Remove the lower sealing cap with the saline solution. If there are any salt crystals on
the electrode, rinse them off carefully with deionized water.
The electrodes are now ready to be installed.
Installing the electrodes
1. Fit the plug of the cable marked "Na+" onto the sodium electrode.
2. Screw on the plug of the cable marked "Na+" finger-tight (right-hand thread).
3. Plug the plug of the cable marked "pH" onto the pH electrode.
4. Screw on the plug of the cable marked "pH" finger-tight (right-hand thread).