4.6.2.4 Formulae for the Preparation of Solutions
A selection of special calculation formulae is available for the Prepare Solutions mode. The appropriate
calculation formula is selected on the Formula Selection submenu:
Fig. 78
A selection of 3 different calculation formulae is available:
W*(100-Fa-Fb)*Fc/Fd - W*(100-Fb) / (100*Fe) +Ff
W*(100-Fa-Fb)*(Fd/Fg ) - W*(100-Fb) / (100*Fg) +Ff
W*(100-Fa-Fb)*Fc / (100*Fd)
Meaning of the individual factors:
W: Weight of the sample in g
Fa: Soluble foreign-matters portion in %
Fb: insoluble foreign-matter portion in %
Fc: Conversion factor for it unit
g/l = 10
mg/l und ppm = 10000
g/100 ml = 1
% = 1
Fd: Target concentration of the solution to be prepared in g/l, mg/l (ppm), g/100 ml, or %
Fe: Specific weight of the weighed-in sample in g/cm³
Ff: Volume correction in ml. this volume correction is the required surplus dosage for compensating the
volume contraction and the specific-weight difference between the sample weight and the solvent (please
observe the note on volume correction)
Fg: Specific weight of the solvent used in g/cm³
Note on volume correction:
The user has to decide on a case-by-case basis whether a volume correction is necessary and according to
which procedure this correction is to be performed. As a rule, this volume correction may be omitted in the case
of solutions with very low percentages of diluted substance.