thermometer vs measuring system

thermometer and measuring system both are nouns.

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

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

thermometer: measuring instrument for measuring temperature
measuring system: instrument that shows the extent or amount or quantity or degree of something

Other hypernyms of thermometer include measuring device, measuring instrument.

thermometer (noun)	measuring system (noun)
measuring instrument for measuring temperature	instrument that shows the extent or amount or quantity or degree of something