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The required equipment for automatic titration include an automatic
titrator equipped with a burette, a standardized titrant, a volumetric
pipette (to measure the sample volume) or analytical balance (to
measureorweighasample),abeaker,asensor,andastirringmechanism.
The automatic titrator must have an accurate liquid-dispensing
system. In high accuracy systems, this is typically amotor-driven piston
burette, a valve system to switch between titrant inlet and outlet, and
a titration tip to dispense the titrant into the sample solution. These
three main subsystems must be as accurate as possible, with very low
gear backlash in the burette drive mechanism, low piston seal flexing,
accurate burette glass cylinder diameter, lowdead volume in the valve,
minimal evaporation/permeation and chemically resistant tubing.
Standards and Standardization
Oneof the substances involved ina titrationmust beusedas a standard
for which the amount of substance present is accurately known. The
standard can be present either in the form of a pure substance or as a
solution. The titrant solution can be standardized in two ways; using a
primary standard, or more commonly, titrating it against a previously
standardized solution.
4
Titration
4.3
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