Hanna Instruments HI 84430 User Manual

Page 15

Verify: The instrument has been calibrated (pH and pump) before performing a lot of titrations.

An electrode calibration in at least one point (8.30 pH buffer) is recommended.

• Sample preparation: For all measurement samples,

pour 50 mL of sample into the beaker provided. Place the
stir bar into the beaker and then place the beaker in the
appropriate place on the instrument top.

Notes: • Water samples must be collected and stored in

capped botlles. Avoid disturbing any sediment in
the sample.

• For samples containing metallic ions (iron,

aluminium, chromium, manganesse) it is neccesary
to add few drops (4-5) of an additional reagent
(HI 84430-58) in order to increase the rate of
hydrolysis at the metal ions present. Boil the
solution 2-4 minute and cool to room temperature
before titration.

• Place the electrode holder on the top of the beaker and

secure it by turning clockwise.

• Insert the temperature probe into the dedicated guide

tube.

• Immerse the pH electrode approximatively 2 cm (0.8”) into

the sample to be tested paying attention not to touch the
stir bar. Use O-Rings provided to secure the pH electrode
in holder.

• Insert the dosing tip in the appropriate holder place.

TITRATION PROCEDURE

• After the pump calibration is complete a confirmation message is displayed for a few seconds,

then the instrument will return to the titrator calibration menu and will display the new time and
date for the last pump calibration.

Notes: • The calibration of the pump is dependent on acidity range selected during SETUP.

• If an erroneous situation is encountered during the calibration, an error message is

displayed and the calibration can be restarted by pressing Restart.

• If the calibration doesn’t complete within 6 minutes the error message “Too much

standard” will be displayed and the calibration can be restarted by pressing Restart
after a new standard is prepared.