… and apparatus for physical or chemical analysis (for example, polarimeters, refractometers, spectrometers, gas or …
Explanatory notes
… and apparatus for physical or chemical analysis (for example, polarimeters, refractometers, spectrometers, gas or … smoke detectors , used in furnaces, ovens, etc., for example, in which a beam of light (or infra‑red) rays is … optical processes and analyses (for determining, for example, degree of concentration, degree of brilliance or …