flow meter vs measuring device

flow meter and measuring device both are nouns.

Word	Noun	Adjective	Verb	Adverb
flow meter	Yes	No	No	No
measuring device	Yes	No	No	No

As nouns, measuring device is a hypernym of flow meter; that is, measuring device is a word with a broader meaning than flow meter:

flow meter: a device used to measure mass or volumetric flow rate of a liquid or gas.
measuring device: instrument that shows the extent or amount or quantity or degree of something

Other hypernyms of flow meter include device, measuring instrument, measuring system.

flow meter (noun)	measuring device (noun)
a device used to measure mass or volumetric flow rate of a liquid or gas.	instrument that shows the extent or amount or quantity or degree of something