As nouns the difference between wavelength and spectrometry

is that wavelength is the length of a single cycle of a wave, as measured by the distance between one peak or trough of a wave and the next; it is often designated in physics as , and corresponds to the velocity of the wave divided by its frequency while spectrometry is (physics|analytical chemistry) the measurement of the wavelength of electromagnetic radiation, especially any of several techniques used to analyze the structure of molecules; the measurement of spectra of things other than radiation, such as the masses of molecules and their breakdown products.