Hanna Instruments HI 904 - Manual (Page 97)

7-3
AUXILIARY FUNCTIONS
7 AUXILIARY FUNCTIONS
7.1 Air Pump
The air pump is used to add or remove the reagent in the titration vessel without exposure
to atmospheric moisture.
To start the air pump, press
from the Idle screen.
The air pump can be stopped by pressing .
7.1.1 Filling the Vessel
To add reagent to the titration vessel:
1. Set up the reagent and waste bottle assemblies ( see Section 2.3.5 Reagent, Waste
Bottle Assembly).
2. Attach the Reagent Exchange Adapter to the dedicated port on the titration vessel.
Ensure that the reagent and waste tubes are properly attached to the Reagent
Exchange Adapter by tightening the compression caps.
3. Depress the button on the top of the pump housing. Pressing the rubberized
button creates a seal which provides the pressure required for the reagent to flow
into the cell. Hold the button down until the level of reagent inside the cell reaches
the ‘min’ indicator line. If the reagent is not flowing, or is flowing very slowly,
verify that the bottle top assemblies are properly assembled, tightly sealed and that
the liquid handling tubing reaches the bottom of the reagent bottle.
4. When the level of reagent inside the titration cell reaches the ‘min’ line release the
button and deactivate the air pump with the option key.
5. Return the Reagent Exchange Adapter to its holder. Return the glass stopper to the
titration vessel port.
7.1.2 Emptying the Vessel
To remove the waste from the titration vessel:
1. Set up the reagent and waste bottle assemblies ( see Section 2.3.5 Reagent, Waste
Bottle Assembly)
2. Attach the Reagent Exchange Adapter to the dedicated port on the titration vessel.
Ensure that the reagent and waste tubes are properly attached to the Reagent
Exchange Adapter by tightening the compression caps.
3. Loosen the waste tube compression cap slightly and slide the waste tube down
until it reaches the bottom of the vessel.
4. Press and hold the button until all of the waste is removed from the vessel.
5. Return the waste tube back into its original position and re-tighten the cap.
6. Return the Reagent Exchange Adapter to its holder. Return the glass stopper to the
titration vessel port.