The Ocean Optics Nanocalc instrument is a UV-visible-NIR thin film analyser which can provide a measurement of the thickness of multilayer films. The instrument measures light reflected perpendicular to a sample surface which can provide information on the thickness of up to 4 layers in a sample, and is useful for an independent comparison with film-thickness measurements obtained on the MRD. The wavelengths available range from 250nm to 850nm, which enable measurement of film thickness from 10nm up to 20micron.