external reflection spectroscopy

https://doi.org/10.1351/goldbook.08599
Measurement method of spectroscopy in which radiation is reflected from a sample of higher refractive index than that of the incident medium.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 746 [Terms] [Paper]