Hanna Instruments HI 901 - Manual (Page 78)

5-38
METHODS
This calculation formula is used as an approximation of the sample concentration (sample
max conc.). This formula can be used when we have an expected sample concentration (eg.
we know that the sample concentration must be around 1 M (mol/L)).
If we don’t have an expected sample concentration, then from the View/Modify Method screen:
• highlight the Titrant 1 Entry option, by pressing .
• highlight Fixed By User option and press , you will be prompted to type the
volume of titrant 1 to be dispensed in the first stage of the back titration.
With this approximation, the titrator will calculate the volume of titrant 1 needed to consume
the sample and multiply it by an excess factor in order to raise or to lower the amount of
titrant 1 dispensed.
When the parameters from the formula are set, press
to proceed to the next formula
used in the back titration algorithm.
This formula is used to calculate the remaining volume of titrant 1 after the reaction with the
sample.
In order to calculate this volume, the remaining volume of titrant 1 is titrated (pH/mV
equivalence point titration) with the titrant 2.
After the excess (remaining) volume of titrant 1 is calculated, the following formula is used
to calculate the exact volume of titrant 1 that was consumed by the sample:
V1 = V1tot – V1excess