Hach-Lange TITRALAB Users Guide - Manual (Page 65)

Programming guidelines 65
g. Blank: A blank or blank sample is usually a solvent used to dissolve
or dilute the sample. This blank may contain traces of the species
you are analysing. Select Yes for Blank when you want to
subtract the volume of titrant used to titrate the solvent from the
volume found for the dissolved or diluted sample.
h. QC sample: the concentration of a QC sample is known accurately
and the composition is close as possible to that of the samples to
be analysed. QC measurements enable you to perform quality
control tests on the method used. Refer to the Reference Manual for
more information concerning this option. Select Yes for QC
sample to perform measurements on QC samples.