5. Significance and Use
5.1 This test method is suitable for setting specifications on
the materials referenced in 1.1. It may also be used as an
internal quality control tool and in development or research
work.
5.2 The color developed in the acid layer gives an indication
of impurities which if sulfonated would cause the material to
be discolored.
6. Apparatus
6.1 Containers for Color Standards—Clear and
unblemished, clean, French square, flint-glass, flat-bottom,
glass-stoppered, 30-mL capacity bottles holding 31 to 33 mL
when filled to the neck.4 The bottles shall be labeled with the
reference number of the color standard they contain (see 11.2).
6.2 Test Containers—Containers exactly like those described
in 6.1 except that each French square bottle shall be
marked by etching to show when the bottle contains the
volume of 7 and 28 mL, respectively. Colored crayons and
similar markers shall not be used for marking the bottles