Chemical analyzer for industrial process control

An optical chemical analyzer comprising:

• a laser module including a laser source;
• a free-space optics module including a filter arrangement comprising at least one excitation blocking filter to reduce or eliminate undesired radiation at the wavelength of said laser source, wherein said optics module transfers radiation of said laser source through an optical window or lens to a sample located outside said analyzer and at a standoff from said analyzer, said optics module collects scattered Raman radiation from said sample through said optical window or lens and transfers said collected Raman radiation to a photometric detector module, said photometric module including a second filter arrangement comprising at least one fixed-wavelength extraction filter and at least one photodetector, each of said extraction filter extracts one or more spectral bands from said collected Raman radiation so as to generate quantitative measurement of analyte concentration;
• and
• a control microprocessor.