is a standardized method for determining water content of
liquid petroleum products (ASTM-D-1744) and
crude oil (ASTM-D-4377 and
D-4928), using the Karl Fischer reagent
ethylene glycol monomethyl ether solution. Depending on the test, either the
standard reagent containing pyridine or pyridine-free Karl Fischer diluted
with xylene is used. A current is applied to electrodes immersed in the
titration mixture. The material to be analyzed is titrated with the reagent
to an electrometric end point, i.e., when the potentiometer needle remains
deflected from the reference point. The water content in parts per million
can be calculated from the milliliters of reagent used in the titration.
Also see crackle test.