photometer vs measuring device

photometer and measuring device both are nouns.

Word	Noun	Adjective	Verb	Adverb
photometer	Yes	No	No	No
measuring device	Yes	No	No	No

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

photometer: measuring instrument for measuring the luminous intensity of a source by comparing it (visually or photoelectrically) with a standard source
measuring device: instrument that shows the extent or amount or quantity or degree of something

Other hypernyms of photometer include measuring instrument, measuring system.

photometer (noun)	measuring device (noun)
photographic equipment that measures the intensity of light	instrument that shows the extent or amount or quantity or degree of something
measuring instrument for measuring the luminous intensity of a source by comparing it (visually or photoelectrically) with a standard source