ALTANA Liquid Color Standards Manual - Manual (Page 7)

6
Operation
Pour a sample of the test liquid into an empty
color comparison tube (Catalog # CL-6756). Insert
the filled tube in the space between the standards
which appear closest in color to the sample.
Determine if the color appears to be equal to,
slightly more, or slightly less in intensity than the
color of the adjoining standards. Express your
conclusion numerically; i.e., if the sample appears
identical to 8, give it a value of 8. If it is slightly
darker than 14 but much lighter than 15, call it
14+. If it is slightly lighter than 14, call it 14-. If the
color appears to be between 4 and 5, but no
closer to one than the other, give it a score or
4.5 or 4-5.
Operation