Clue: Stripping off, never mind getting a measuring device (6)
Answer: ETALON
Explanation: Definition: a measuring device
LET ALONE ("never mind"), minus its outer letters. (Not [G]ET ALON[G], which I was trying to justify to myself for a while) The etalon, used for measuring wavelengths of light, is also known as the Fabry–Pérot interferometer