Abstract: An optical apparatus for measurement of industrial chemical processes. The analyzer uses Raman scattering and performs measurement of chemical concentrations in continuous or batch processes. The analyzer operates at a standoff distance from the analyte (or analytes) and can measure concentrations through an optical port, facilitating continuous, non-destructive, and non-invasive analysis without extracting the analyte or analytes from the process. The analyzer can measure one or several solid, liquid, or gaseous analytes, or a mixture thereof.