quantity, defined by a conventional measurement procedure, for which a total ordering relation can be established, according to magnitude, with other quantities of the same kind, but for which no algebraic operations among those quantities exist
EXAMPLE 1 Rockwell C hardness.
EXAMPLE 2 Octane number for petroleum fuel.
EXAMPLE 3 Earthquake strength on the Richter scale.
EXAMPLE 4 Subjective level of abdominal pain on a scale from zero to five.
NOTE 2 Ordinal quantities are arranged according to ordinal quantity-value scales (see 1.28).