phosphoroscope

[ fos-fawr-uh-skohp, -for- ]
/ fɒsˈfɔr əˌskoʊp, -ˈfɒr- /

noun

an instrument for measuring the duration of evanescent phosphorescence in different substances.

Origin of phosphoroscope

First recorded in 1855–60; phosphoro- + -scope

British Dictionary definitions for phosphoroscope

phosphoroscope
/ (fɒsˈfɒrəˌskəʊp) /

noun

an instrument for measuring the duration of phosphorescence after the source of radiation causing it has been removed