… (for example, polarimeters, refractometers, spectrometers, gas or smoke analysis apparatus); instruments and apparatus for measuring or checking viscosity, porosity, expansion, …
Explanatory notes
… (for example, polarimeters, refractometers, spectrometers, gas or smoke analysis apparatus); instruments and apparatus … include : (i) Orsat’s apparatus consisting mainly of an aspirating bottle, one or more absorption bulbs and a …