COMPARATOR
Noun
comparator (plural comparators)
Any device for comparing a physical property of two objects, or an object with a standard.
An electronic device that compares two voltages, currents or streams of data.
(law) anything that serves comparison
Synonyms
• dial gauge
• dial indicator
• indicator
Source: Wiktionary
Com"pa*ra`tor ( or ), n. Etym: [L., a comparater.] (Physics)
Definition: An instrument or machine for comparing anything to be measured
with a standard measure; -- applied especially to a machine for
comparing standards of length.
Source: Webster’s Unabridged Dictionary 1913 Edition