Reflectance or Transmission Spectroscopy

**Semantic type:** Laboratory Procedure

**Definition:** The spectroscopic analysis of light reflected from a polished sample. The peaks of reflectance/transmittance occur in the same spectral region where the sample absorbs light. In near infrared (IR) reflectance/transmission spectroscopy (NIRS), the reflectance signals result from bending and stretching vibrations in molecular bonds between carbon, nitrogen, hydrogen, and oxygen. (from FRTR Field Sampling and Analysis Technologies Reference Guide (online))

**Synonyms:** - REFLECTANCE SPECTROSCOPY