declinometer vs transit declinometer

declinometer and transit declinometer both are nouns.

Word	Noun	Adjective	Verb	Adverb
declinometer	Yes	No	No	No
transit declinometer	Yes	No	No	No

As nouns, declinometer and transit declinometer are synonyms defined as:

declinometer and transit declinometer: an instrument for measuring magnetic declination

declinometer (noun)	transit declinometer (noun)
an instrument for measuring magnetic declination	an instrument for measuring magnetic declination