Hanna Instruments HI 84431 - Manual (Page 24)

24
PURGE
Purging should be performed:
• whenever the tube of the peristaltic pump is replaced;
• whenever the titrant is changed or a new bottle is used;
• before starting a pump calibration;
• before starting a lot of titrations.
In order to start purging press the Purge key from the titrator main screen. The purging stops
automatically after 5 minutes.
To access the Purge key follow the next steps.
• From the instrument main screen (pH meter screen) press “Titrator” function key.
The instrument will display the next screen if any of the following conditions exist:
- the meter hasn’t been calibrated in 8.30 pH buffer
- the pH calibration has expired
PUMP TUBE INSTALLATION
To mount the new peristaltic pump tube follow next steps:
• Position one peristaltic pump fixing ring on its location.
• Stretch the tube over the peristaltic pump rolls.
• Fix the second pump fixing ring on its location.
• Determine which titrant is required for the expected
alkalinity range selected (see table in Alkalinity Type).
• Attach the tube to the reagent bottle.
Note: Purge the peristaltic pump until drops of reagent appears on the dosing tip by pressing the
PURGE key from the titrator main screen.
To remove the tube of the peristaltic pump follow next steps:
Caution: Purge line with water to remove titrant solution from tube.
• Detach the tubes system from the reagent bottle.
• Grasp one fixing ring of the peristaltic pump tube.
• Pull the tube until the fixing rings are taken out from their location.
• Remove the other side of the tube.