Hanna Instruments HI 901 - Manual (Page 49)

5-9
METHODS
Back Titration
A titration with a pH or mV equivalence point detection, consisting of two titration phases:
• Phase 1 – the sample is consumed by a known volume and concentration of titrant 1.
A sufficient amount of titrant 1 is dispensed to surpass the equivalence point in order
to react quickly with the sample.
• Phase 2 – the excess of titrant 1 is titrated with the titrant 2 to the equivalence point.
Finally, the concentration of the sample will be determined.
Also, if the Back Titration option is chosen, the following settings must be selected:
• Titrant 1 pump: select the pump used in phase 1 of the titration (Pump 1).
• Titrant 2 pump: select the pump used in phase 2 of the titration (Pump 2).
• Break at titrant changing: select “YES” to stop titration temporarily, between the first and
the second phase of the back titration (you can do some tasks in order to perform the
analysis: eg. boiling the sample in order to evaporate the carbon dioxide).
5.5.3 Dosing Type
The Titrator allows two dosing types: Linear Dosing and Dynamic Dosing.