hydrometer vs measuring system

hydrometer and measuring system both are nouns.

Word	Noun	Adjective	Verb	Adverb
hydrometer	Yes	No	No	No
measuring system	Yes	No	No	No

As nouns, measuring system is a hypernym of hydrometer; that is, measuring system is a word with a broader meaning than hydrometer:

hydrometer: a measuring instrument for determining the specific gravity of a liquid or solid
measuring system: instrument that shows the extent or amount or quantity or degree of something

Other hypernyms of hydrometer include measuring device, measuring instrument.

hydrometer (noun)	measuring system (noun)
a measuring instrument for determining the specific gravity of a liquid or solid	instrument that shows the extent or amount or quantity or degree of something